What is the greatest common factor of 18?

Answer 1

You need at least two numbers to find a GCF. There is no common factor for a single number. The Greatest Common Factor (GCF) is the largest factor common to two or more numbers. For example, 17 is the GCF of 34, 51, and 102 because it is the largest number that is a factor common to all three numbers.

Answer 2

18 is the greatest common factor of any two multiples of 18 that differ by 18.

Example 18 is the GCF of 36 and 54, 180 and 198, 270 and 288 etc.

Answer 3

The GCF of a single number is the number itself.