What is the GCF of 15 and 64?
Greatest Common Factor of the numbers, 15 and 64 is the greatest possible number which divides 15 and 64 exactly without any remainder.
Answer: GCF of 15 and 64 is 1
Let us see how to find GCF of 72 and 90
Methods to find GCF of 72 and 90
We will explain two methods to find GCF(15, 64):

Prime factorization Method

Listing the common factors Method
Method1: GCF of 15 and 64 by Prime Factorization
Expressing 15 and 64 as a product of their prime factors:
Prime factorization of 15 is 3 x 5
Prime factorization of 64 is 2 x 2 x 2 x 2 x 2 x 2
The common factors in the prime factorization of 15 and 64 are 1
GCF is the product of the prime factors that are common to prime factorization of 15 and 64
So, GCF(15, 64) = 1
Method2: GCF of 15 and 64 by Listing the Common Factors
Factors of 15 are 1, 3, 5, and 15
Factors of 64 are 1, 2, 4, 8, 16, 32, and 64
So, the common factor of 15 and 64 is 1
The Greatest Common Factor of 15 and 64 from the list is 1
GCF of 15 and 64 is 1
You can find the GCF in any of the above methods but the solution will always remain the same.