greatest common factor

In math, the greatest common factor is the largest number that can divide evenly into two other numbers. For example, the greatest common factor of 12 and 30 is 6.

You can also call the greatest common factor the greatest common divisor. To find it, you first need to break numbers down into their factors (smaller numbers that multiply together to get the original number). Then you can compare all the factors and see if your numbers share any in common — if they do, choose the largest of these, and you've got your greatest common factor. For numbers that don't share another divisor, the greatest common factor is 1.

Definitions of greatest common factor

1. noun

   the largest integer that divides without remainder into a set of integers
   synonyms: greatest common divisor, highest common factor

   type of:

   common divisor, common factor, common measure

   an integer that divides two (or more) other integers evenly