Any of the factors of a number, except the number itself. Sometimes 1 is also excluded.

Factors of 12: 1,2,3,4,6,12

Proper Factors of 12: 1,2,3,4,6

Factors of 12: 1,2,3,4,6,12

Proper Factors of 12: 1,2,3,4,6

See: Factor

Copyright © 2016 MathsIsFun.com