What is the Greatest Common Factor of 21315 and 21330?

Greatest common factor (GCF) of 21315 and 21330 is 15.

GCF(21315,21330) = 15

We will now calculate the prime factors of 21315 and 21330, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21315 and 21330.

How to find the GCF of 21315 and 21330?

We will first find the prime factorization of 21315 and 21330. After we will calculate the factors of 21315 and 21330 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 21330

Prime factors of 21330 are 2, 3, 5, 79. Prime factorization of 21330 in exponential form is:

21330 = 2¹ × 3³ × 5¹ × 79¹

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 21330

List of positive integer factors of 21330 that divides 21315 without a remainder.

1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 79, 90, 135, 158, 237, 270, 395, 474, 711, 790, 1185, 1422, 2133, 2370, 3555, 4266, 7110, 10665

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21315 and 21330. The biggest common factor number is the GCF number.
So the greatest common factor 21315 and 21330 is 15.

Also check out the Least Common Multiple of 21315 and 21330