# What is the greatest common factor of 4 and 23?

The GCF of 4 and 23 is 1

**Definition**: A factor is a divisor - a number that will
evenly divide into another number. The greatest common factor of
two or more numbers is the largest factor that the numbers have in
common.

**Method**:

One way to determine the common factors and greatest common factor is to find all the factors of the numbers and compare them.

The factors of 4 are 1, 2, and 4.

The factors of 23 are 1 and 23.

The only common factor is 1. Therefore, the greatest common factor is 1, which means the numbers are relatively prime.