What is the greatest common factor of 27 and 63?

The GCF of 27 and 63 is 9.

The Greatest Common Factor is the highest number that divides exactly into two or more numbers.

factors of 27: 1, 3, 9, 27

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

The Greatest Common Factor of 27 and 63 is 9.
9
The GCF is 9.