What is the Greatest Common Factor of 21315 and 21321?

Greatest common factor (GCF) of 21315 and 21321 is 3.

GCF(21315,21321) = 3

We will now calculate the prime factors of 21315 and 21321, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21315 and 21321.

How to find the GCF of 21315 and 21321?

We will first find the prime factorization of 21315 and 21321. After we will calculate the factors of 21315 and 21321 and find the biggest common factor number .

Step-1: Prime Factorization of 21315

Prime factors of 21315 are 3, 5, 7, 29. Prime factorization of 21315 in exponential form is:

21315 = 3¹ × 5¹ × 7² × 29¹

Step-2: Prime Factorization of 21321

Prime factors of 21321 are 3, 23, 103. Prime factorization of 21321 in exponential form is:

21321 = 3² × 23¹ × 103¹

Step-3: Factors of 21315

List of positive integer factors of 21315 that divides 21315 without a remainder.

1, 3, 5, 7, 15, 21, 29, 35, 49, 87, 105, 145, 147, 203, 245, 435, 609, 735, 1015, 1421, 3045, 4263, 7105

Step-4: Factors of 21321

List of positive integer factors of 21321 that divides 21315 without a remainder.

1, 3, 9, 23, 69, 103, 207, 309, 927, 2369, 7107

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21315 and 21321. The biggest common factor number is the GCF number.
So the greatest common factor 21315 and 21321 is 3.

Also check out the Least Common Multiple of 21315 and 21321