Common Factors Calculator
This calculator factors a set of positive integers to find the common factors (common divisors) of those integers. Enter the set of numbers you want to factor separating them with commas. Click "Calculate" to see all factors of each number as well as the greatest common factor (GCF).
The factors of a number include all divisors of that number. The factors of 12, for example, are 1, 2, 3, 4, 6 and 12. You can divide 12 by any of these numbers and obtain another whole integer number.
Common factors are factors (divisors) that are in common among a set of numbers. Consider the factors of 27, 54, and 81:
Each of the numbers can be divided by 1, 3, 9, and 27, so you can say that these numbers are common factors of the set of numbers 27, 54, and 81. The largest of the common factors is 27, so you can say that 27 is the greatest common factor of 27, 54, and 81.
See the Factoring Calculator to learn more about finding the factors of a single integer number.