What is the Greatest Common Factor of 9915 and 9920?

Greatest common factor (GCF) of 9915 and 9920 is 5.

GCF(9915,9920) = 5

We will now calculate the prime factors of 9915 and 9920, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 9915 and 9920.

How to find the GCF of 9915 and 9920?

We will first find the prime factorization of 9915 and 9920. After we will calculate the factors of 9915 and 9920 and find the biggest common factor number .

Step-1: Prime Factorization of 9915

Prime factors of 9915 are 3, 5, 661. Prime factorization of 9915 in exponential form is:

9915 = 3¹ × 5¹ × 661¹

Step-2: Prime Factorization of 9920

Prime factors of 9920 are 2, 5, 31. Prime factorization of 9920 in exponential form is:

9920 = 2⁶ × 5¹ × 31¹

Step-3: Factors of 9915

List of positive integer factors of 9915 that divides 9915 without a remainder.

1, 3, 5, 15, 661, 1983, 3305

Step-4: Factors of 9920

List of positive integer factors of 9920 that divides 9915 without a remainder.

1, 2, 4, 5, 8, 10, 16, 20, 31, 32, 40, 62, 64, 80, 124, 155, 160, 248, 310, 320, 496, 620, 992, 1240, 1984, 2480, 4960

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 9915 and 9920. The biggest common factor number is the GCF number.
So the greatest common factor 9915 and 9920 is 5.

Also check out the Least Common Multiple of 9915 and 9920