What is the greatest common factor of 19 and 27?

The GCF of 19 and 27 is 1.

First you have to find the factors of each of the numbers given 27 and 19

Factors of 27 = 1, 3, 9 and 27

Factors of 19 = 1, and 19

Common factor is 1

Therefore, 1 is the only factor that these numbers have in common .

Hence, GCF of 27 and 19 is 1