Greatest common divisor calculator



GCD(21, 72) = 3


21 = 3×7
72 = 23×32
GCD = 3

21 / 3 = 7

72 / 3 = 24

What is GCD?

The greatest common divisor (gcd/GCD), or the greatest common factor (gcf), or highest common factor (hcf), of two or more integers (at least one of which is not zero), is the largest positive integer that divides the numbers without a remainder.

See divisors of numbers 3, 21, 72.