What is the greatest common factor of 36 and 54?

The greatest common factor (GCF) of 36 and 54 is 18. This is because 18 is the largest number that divides evenly into both 36 and 54. To find the GCF, you can list the factors of both numbers and find the largest one they have in common. The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36. The factors of 54 are 1, 2, 3, 6, 9, 18, 27, and 54. The largest number they have in common is 18, so that is the GCF.