What is the greatest common factor of 27 45 and 63?

The greatest common factor (GCF) is often also called the greatest common divisor (GCD) or highest common factor (HCF). Keep in mind that these different terms all refer to the same thing: the largest integer which evenly divides two or more numbers.

The greatest common factor of 27, 45, and 63 is 9

The factors of 27 are: 1, 3, 9, 27

The factors of 45 are: 1, 5, 9, 45

The factors of 63 are: 1, 3, 7, 9, 21, 63

The greatest common factor among them all is 9.
The greatest common factor of the numbers 27, 45 and 63 is 9.