What is the greatest common factor of 999?

There is not a greatest common factor of a single number, such as 999, because there cannot be a greatest common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common. The greatest common factor is the largest factor that all the numbers being compared have in common.

The factors of 999 are 1, 3, 9, 27, 37, 111, 333, and 999.

The prime factors of 999 are 3, 3, 3, and 37.

Examples:

The greatest common factor of 54 and 999 is 27.

The greatest common factor of 185 and 999 is 37.

The greatest common factor of 999 and 1001 is 1.