What is the Greatest Common Factor of 915 and 921?

Greatest common factor (GCF) of 915 and 921 is 3.

GCF(915,921) = 3

We will now calculate the prime factors of 915 and 921, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 915 and 921.

How to find the GCF of 915 and 921?

We will first find the prime factorization of 915 and 921. After we will calculate the factors of 915 and 921 and find the biggest common factor number .

Step-1: Prime Factorization of 915

Prime factors of 915 are 3, 5, 61. Prime factorization of 915 in exponential form is:

915 = 3¹ × 5¹ × 61¹

Step-2: Prime Factorization of 921

Prime factors of 921 are 3, 307. Prime factorization of 921 in exponential form is:

921 = 3¹ × 307¹

Step-3: Factors of 915

List of positive integer factors of 915 that divides 915 without a remainder.

1, 3, 5, 15, 61, 183, 305

Step-4: Factors of 921

List of positive integer factors of 921 that divides 915 without a remainder.

1, 3, 307

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 915 and 921. The biggest common factor number is the GCF number.
So the greatest common factor 915 and 921 is 3.

Also check out the Least Common Multiple of 915 and 921