What is the Greatest Common Factor of 21255 and 21270?

Greatest common factor (GCF) of 21255 and 21270 is 15.

GCF(21255,21270) = 15

We will now calculate the prime factors of 21255 and 21270, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21255 and 21270.

How to find the GCF of 21255 and 21270?

We will first find the prime factorization of 21255 and 21270. After we will calculate the factors of 21255 and 21270 and find the biggest common factor number .

Step-1: Prime Factorization of 21255

Prime factors of 21255 are 3, 5, 13, 109. Prime factorization of 21255 in exponential form is:

21255 = 3¹ × 5¹ × 13¹ × 109¹

Step-2: Prime Factorization of 21270

Prime factors of 21270 are 2, 3, 5, 709. Prime factorization of 21270 in exponential form is:

21270 = 2¹ × 3¹ × 5¹ × 709¹

Step-3: Factors of 21255

List of positive integer factors of 21255 that divides 21255 without a remainder.

1, 3, 5, 13, 15, 39, 65, 109, 195, 327, 545, 1417, 1635, 4251, 7085

Step-4: Factors of 21270

List of positive integer factors of 21270 that divides 21255 without a remainder.

1, 2, 3, 5, 6, 10, 15, 30, 709, 1418, 2127, 3545, 4254, 7090, 10635

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21255 and 21270. The biggest common factor number is the GCF number.
So the greatest common factor 21255 and 21270 is 15.

Also check out the Least Common Multiple of 21255 and 21270