What is the least common factor of 25?

The least common factor is a term often mistakenly given to either the greatest common factor (GCF) or the least common multiple (LCM). This term is not often used because it does not describe a useful relationship between numbers. Since 1 evenly divides all integers, 1 is technically the least common factor for any set of integers.

Since 25 is a single number, you could say that it shares all of its factors with itself. The smallest non-one factor of 25 is 5.