List all the factors (divisors) of a number, with their count and sum. Enter a whole number.
Usage Tip
Factors pair up: for 24, 1×24, 2×12, 3×8, 4×6 — find one and you get its partner for free.
Found by checking up to the square root and pairing
A prime has exactly two factors; a perfect number equals the sum of its proper factors.
A number with exactly two factors is prime.
Perfect numbers (6, 28, 496) equal the sum of their proper divisors.
The factors of a number are the whole numbers that divide it evenly with no remainder. The factors of 12 are 1, 2, 3, 4, 6, and 12. Factors come in pairs that multiply to the original number, so you only need to test up to its square root to find them all.
A number with exactly two factors, 1 and itself, is prime, and a number with more than two is composite. A perfect square has an odd number of factors, because one of its pairs repeats. The sum of the factors is used in the study of perfect numbers, where a number equals the sum of its proper factors. Factors are handy for splitting items into equal groups or arranging rows and columns.