Include your email address to get a message when this question is answered. Learn more Finding how many factors are in a number is as easy a 1 2 3 if you know how to do it. Why does Isaiah 17 begin as a prophetic disciplinary declaration against the Arameans , but then later on also includes the Israelites? How to Find Prime Factorization: 14 Steps (with Pictures) - wikiHow This does not tell you how to, All tip submissions are carefully reviewed before being published. The % (remainder) operator is the one to use here. 2 Temporary policy: Generative AI (e.g., ChatGPT) is banned, Getting a List from an integer which modulo result is equal to 0 without using loop. Now, there is repeated multiplication, so we have to stop the multiplication. Put one or both of these in a list, and you have all of the factors. [1] They wont promote me if i am not able to present this one clearly. Enjoy! Program to get prime factors of whole numbers in javascript code. Rather than taking the square root, you can restructure the loop: for(int factor = 1; factor*factor <= number; ++factor). Note that it's not just an off-by-one; for larger numbers it will be off by more. Also, that needs to be rounded up. Factoring only has to do with multiplication and division, since you are determining the factors of a number. Has this "thinner" Cantor set been defined and studied before? I've just started solving Project Euler puzzles myself. It is customary but not mandatory, unless the instructions tell you to do so. Get list of int values in a number that was multiplied by 2, Fastest way to find all the divisors of a large number. Are high yield savings accounts as secure as money market checking accounts? This is what I went with after all the help from everyone. It's 10 cents higher than it was a month ago but still lower than a record-high of $5 per gallon in . Take 72, for example, but the number could be denoted by a variable. If youre going to use a library, may as well make it the right one: SymPy, as seen in Evgeni Sergeevs answer. To find the factors of a number, we need to use the multiplication or division method. of factors/2, Example 1 : Find the number of factors of 98 and also find the sum and product of all factors, Solution : First write the number 98 into prime factorization, 98 = 21 x 72 Here A = 2 , B = 7 , p= 1 , q = 2, Number of factors for the number 98 = (p + 1)(q +1) = 2 x 3 = 6, Sum of all factors of 98 = = 3 x 57 = 171, Product of all factors of number 98 = (98)6/2 = (98)3 = 941192, Example 2 : Find the number of factors of 588 and also find the sum and product of all factors, Solution : First write the number 588 into prime factorization, 588 = 2 x 294 = 2x 2 x 147 = 2 x 2 x 7 x 21 = 2 x 2 x 7 x 7 x 3, 588 = 22 x 31 x 72 Here A = 2 , B = 3 , C = 7 , p= 2 , q = 1 and r =2, Number of factors = (p + 1)(q +1)(r +1) = 3 x 2 x 3 = 18, Sum of all factors of 588 = 7 x 4 x 57 = 1596, Product of all factors of number 588 = (588)18/2 = (588)9, Example 3 : Find the number of odd, even, perfect square, perfect cube factors of 4500, Solution: First write the number 4500 into prime factorization, 4500 = 45 x 100 = 9 x 5 x 10 x 10 = 3 x 3 x 5 x 5 x 2 x 5 x 2, 4500 = 22 x 32 x 53 Here consider A = 2 , B = 3 , C = 5 , p= 2 , q = 2 and r = 3, Here identifying that odd number are 3 and 5, Numbers of odd factors of number 4500 = (q + 1 ) (r + 1) = 3 x 4 = 12, Total number of factors = (p + 1)(q +1)(r +1) = 3 x 3 x 4 =36, Numbers of even factors of number = Total number of factors Numbers of odd factors = 36 12 = 24, Number of perfect square factors of number 4500 = 2 x 2 x 2 = 8, ( 22 20 , 22 ; 32 30 , 32 & 52 50 , 52 ), Number of perfect cube factors of number 4500 = 1 x 1 x 2 = 2, ( 22 20 32 30 , & 52 50 , 53 ), Example 4 : Find the number of odd, even, perfect square, perfect cube factors of 5040, Solution: First write the number 5040 into prime factorization, 5040 = 504 x 10 = 4 x 126 x 5 x 2 = 2 x 2 x 18 x 7 x 5 x 2 = 2 x 2 x 3 x 3 x 2 x 7 x 5 x 2, 5040 = 24 x 32 x 71 Here consider A = 2 , B = 3 , C = 7 , p= 4 , q = 2 and r = 1, Here identifying that odd number are 3 and 7, Numbers of odd factors of number 5040 = (q + 1 ) (r + 1) = 3 x 2 = 6, Total number of factors = (p + 1)(q +1)(r +1) = 5 x 3 x 2 = 30, Numbers of even factors of number = Total number of factors Numbers of odd factors = 30 6 = 24, Number of perfect square factors of number 5040 = 3 x 2 x 1 = 6, ( 22 20 , 22, 24 ; 32 30 , 32 & 71 70 ), Number of perfect cube factors of number 5040 = 2 x 1 x 1 = 2, ( 22 20 , 23 ; 32 30 , & 72 70 ), Formulas for Sum of n Consecutive numbers. Can you help me optimize this code for finding factors of a number? Why Are Gas Prices So High? - Forbes Advisor If you want to learn strategies to help factor large numbers, keep reading the article! Solution : First write the number 98 into prime factorization 98 = 2 x 49 = 2x 7 x 7 98 = 21 x 72 Here A = 2 , B = 7 , p= 1 , q = 2 Number of factors for the number 98 = (p + 1) (q +1) = 2 x 3 = 6 Sum of all factors of 98 = = 3 x 57 = 171 Product of all factors of number 98 = (98)6/2 = (98)3 = 941192 AM, GM and HM, Integral and Double Integral calculus Example with Solution | Allmathtricks, Pyramid Geometry Formulas and Properties | Frustum of Pyramid, Centroid of the triangle formula with examples | coordinate geometry, Coordinate geometry introduction | Locating of coordinate points, Frustum of cone formulaswith examples | Surface area and Volume, Surface Area and Volume of a Prism Formulas, rectangular and triangular, Surface Area and Volume of a Cone formulas with examples Allmathtricks, Volume and Surface Area of a Cylinder Formulas Right Circular Cylinder. I figured I'd share it and see what you all think. Level up your tech skills and stay ahead of the curve. Thanks to all authors for creating a page that has been read 355,638 times. It outperforms all the other versions I tested, including dansalmo's, Jason Schorn's, oxrock's, agf's, steveha's, and eryksun's solutions, though oxrock's is by far the closest. How to find the factors of a number given the prime factorization? And one more solution. If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. 72 should be factorized into 2 and 36, 2, 6, and 6, and finally, 2, 2, 3, 2, 3, which equals 2. Here's my version: The if sq*sq != num: condition is necessary for numbers like 12, where the square root is not an integer, but the floor of the square root is a factor. This answer might be helpful for those who just need quick solution, and they are doing some basic stuff, Great stuff! Use it to try out great new products and services nationwide without paying full pricewine, food delivery, clothing and more. Instead of writing down another 2, we'll try the next prime number: 3. I'm brushing up on my math programming. But it's not really much faster than the reduce version, roughly 4% faster based on my measurements. How do you find all the factors of a number on a calculator? 72 2. if we have the lower divisor we can get he upper one easily. References. Thanks to all authors for creating a page that has been read 748,831 times. Sign up for wikiHow's weekly email newsletter. and therefore still very limited in its efficiency (especially for big numbers without small divisors). Not sure if it has any advantages other than being readable..: I came here just looking for a solution to this problem for myself. What triggers the new fist bump animation? Of course this produces a lot of unnecessary calls to functions. The national average price of gas was $3.87 per gallon on Oct. 6, according to data from AAA. @TristanForward: Thats not how for loops work in Python. And this is the extension version of the method for int type: Thanks for contributing an answer to Stack Overflow! Next, determine whether those 2 numbers can be factored again. If none of the factors you try up to this point divide evenly, you're probably trying to factor a prime number and thus are finished with the factoring process. Step 2 : Take all exponents and add one to each of them. Just keep the max as double (don't cast it to an int) and change to loop to be exclusive not inclusive. (That's how python is made.) Were there any planes used in WWII that were able to shoot their own tail? Cross it out once on each list and write it on a new line. What are the Factors? If x % y == 0 then x is divisible by y. For example, the factors of 42 should return a list of 8 values. See the documentation linked above. Find centralized, trusted content and collaborate around the technologies you use most. By implementing @agf's solution with numpy and it turned out at average 8x faster. In fact we don't have to check for factors not to be square root in each iteration from the accepted answer proposed by chris fixed by Jon, which could slow down the method when the integer is large by adding an unnecessary Boolean check and a division. TAPIWA MAKORE MURDER: COURT HANDS DOWN SENTENCE - Facebook This article has been viewed 748,831 times. Can the people who let their animals roam on the road be punished? Factors are the numbers you multiply together to get another number. Notice that the numbers of the x-axis are not the input to the functions. Multiply the modified exponents together. this is python3; the division // should be the only thing you need to adapt for python 2 (add from __future__ import division). Bass line and chord mismatch - Afternoon in Paris. (Ep. I doubt I'll need to use checks for my own implementation but I'm including them just for completeness (at least partially). Note that the itertools version is building a tuple and passing it to flatten_iter(). @unseen_rider: That doesnt sound right. 288 = 2 2 2 2 2 3 3= 2 5. For example, to find the factors of 2, we have to arrange two objects differently. Your email address will not be published. In this article provided formulas of Surface Area and Volume of a Sphere and a Hemisphere with examples. By using our site, you agree to our. Connect and share knowledge within a single location that is structured and easy to search. 35, 450, or 764,545,230). In ticks. If we were to factor further, we'd have to factor to (2 1) ((2 1)(3 1)), which isn't typically useful, so it's usually avoided. rev2023.7.17.43537. I have a Python list of the prime factors of a number. Deutsche Bahn Sparpreis Europa ticket validity. By the way, sympy.divisors may be a better match to answer this question. See below: For the purpose of our example, let's choose a 4-digit number to factor -, In our example, since 6,552 is even, we know that 2 is its smallest prime factor. edit: I know it sounds homeworky. What's it called when multiple concepts are combined into a single problem? What is the most efficient way of finding all the factors of a number in Python? 3,276 2 = 1,638, so att the bottom of the left column, we'll write another, In our example, we've reached 819. Similarly, we can find the factors of 6. Don't use, It doesn't produces all factors of a number. I wanted to see if I could rewrite it to avoid using reduce(). Very late but the accepted answer (a while back) didn't not give the correct results. But for me, this function just returns 1,2,3 and 7. As expected, the accepted answer is about the same speed as, This is by far the fastest method here for very large numbers. EASY WAY TO FIND FACTORS OF A LARGE NUMBER - onlinemath4all Modern cryptography relies on there being no such solution. I have a Python list of the prime factors of a number. The simplest way of finding factors of a number: I've tried most of these wonderful answers with timeit to compare their efficiency versus my simple function and yet I constantly see mine outperform those listed here. This article has been viewed 355,638 times. This doesn't handle duplicate factors well - try 81 for example. Doping threaded gas pipes -- which threads are the "last" threads? To factor a number, first find 2 numbers that multiply to make that number. Unless I am missing something I would suggest, if you must do it this way, using int(ceil(sqrt(x))). Find all factors of a Natural Number Read Discuss Courses Practice Given a natural number n, print all distinct divisors of it. % of people told us that this article helped them. Just find one and you can return both by just dividing the original number by the found one. Loop from 1 to the square root of the number, call the index "i". Making statements based on opinion; back them up with references or personal experience. Just wanted to let you know. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/2\/2e\/Factor-a-Number-Step-1-Version-4.jpg\/v4-460px-Factor-a-Number-Step-1-Version-4.jpg","bigUrl":"\/images\/thumb\/2\/2e\/Factor-a-Number-Step-1-Version-4.jpg\/aid40992-v4-728px-Factor-a-Number-Step-1-Version-4.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"