This free online factor calculator lists every factor of a positive integer and breaks it down into its prime factorization. It's a handy tool for finding common factors, checking divisibility, or studying number theory.
How to Use the Factor Calculator
Enter a positive whole number in the "Number" field.
Click "Calculate" to see the full list of factors.
Check the "Prime Factorization" line to see the number expressed as a product of primes.
Frequently Asked Questions
It checks every integer from 1 up to the square root of your number. Whenever it finds a divisor i, it records both i and n / i as factors, which is much faster than checking every number up to n. For example, the factors of 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60.
Prime factorization expresses a number as a product of prime numbers. The calculator repeatedly divides your number by the smallest possible prime until only 1 remains. For example, 60 = 2^2 × 3 × 5.
Factoring is only defined for positive whole numbers, so the calculator requires a positive integer and shows "Please enter a positive integer" otherwise. Numbers above 10,000,000 are also rejected with "Number too large" to keep the calculation fast.
Yes, it's completely free with no sign-up required.