What is the Greatest Common Factor of 21243 and 21255?

Greatest common factor (GCF) of 21243 and 21255 is 3.

GCF(21243,21255) = 3

We will now calculate the prime factors of 21243 and 21255, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21243 and 21255.

How to find the GCF of 21243 and 21255?

We will first find the prime factorization of 21243 and 21255. After we will calculate the factors of 21243 and 21255 and find the biggest common factor number .

Step-1: Prime Factorization of 21243

Prime factors of 21243 are 3, 73, 97. Prime factorization of 21243 in exponential form is:

21243 = 3¹ × 73¹ × 97¹

Step-2: 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-3: Factors of 21243

List of positive integer factors of 21243 that divides 21243 without a remainder.

1, 3, 73, 97, 219, 291, 7081

Step-4: Factors of 21255

List of positive integer factors of 21255 that divides 21243 without a remainder.

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

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21243 and 21255. The biggest common factor number is the GCF number.
So the greatest common factor 21243 and 21255 is 3.

Also check out the Least Common Multiple of 21243 and 21255