Calculate Number Divisors

Yes, completely secure. The tool runs 100% client-side in your browser with no server calls, analytics on the input, or data retention of any kind.

Yes, it is entirely free – no sign-up, no subscription, no usage limits. Calculate divisors as many times as you need.

Yes. After the page loads once, every calculation happens locally in your browser. You can disconnect from the internet and the tool keeps working.

A divisor (or factor) of n is a positive integer that divides n with remainder 0. For example, the divisors of 12 are 1, 2, 3, 4, 6, and 12.

A perfect number equals the sum of its proper divisors (all divisors except n itself). The first few are 6, 28, 496, and 8,128. Every known perfect number is even and linked to Mersenne primes.

Abundant means the proper-divisor sum exceeds n (12 → 1+2+3+4+6 = 16 > 12). Deficient means it falls short (8 → 1+2+4 = 7 < 8). Every prime p is deficient because its only proper divisor is 1.

Up to 2^53 – 1 = 9,007,199,254,740,991, which is JavaScript’s exact-integer limit. The √n loop handles numbers near that ceiling in well under a second.

Instead of testing every integer up to n, the tool iterates only from 1 to √n. For each divisor i found, it also records the pair n/i. That turns an O(n) search into O(√n).

Yes, the calculator is fully responsive. The numeric keypad appears automatically on iOS and Android thanks to inputmode="numeric".

Yes, every divisor is sorted in ascending order from 1 up to n itself, regardless of the order they were discovered during the √n loop.