What is the Greatest Common Factor of 28209 and 28215?

Greatest common factor (GCF) of 28209 and 28215 is 3.

GCF(28209,28215) = 3

We will now calculate the prime factors of 28209 and 28215, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 28209 and 28215.

How to find the GCF of 28209 and 28215?

We will first find the prime factorization of 28209 and 28215. After we will calculate the factors of 28209 and 28215 and find the biggest common factor number .

Step-1: Prime Factorization of 28209

Prime factors of 28209 are 3, 9403. Prime factorization of 28209 in exponential form is:

28209 = 3¹ × 9403¹

Step-2: Prime Factorization of 28215

Prime factors of 28215 are 3, 5, 11, 19. Prime factorization of 28215 in exponential form is:

28215 = 3³ × 5¹ × 11¹ × 19¹

Step-3: Factors of 28209

List of positive integer factors of 28209 that divides 28209 without a remainder.

1, 3, 9403

Step-4: Factors of 28215

List of positive integer factors of 28215 that divides 28209 without a remainder.

1, 3, 5, 9, 11, 15, 19, 27, 33, 45, 55, 57, 95, 99, 135, 165, 171, 209, 285, 297, 495, 513, 627, 855, 1045, 1485, 1881, 2565, 3135, 5643, 9405

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 28209 and 28215. The biggest common factor number is the GCF number.
So the greatest common factor 28209 and 28215 is 3.

Also check out the Least Common Multiple of 28209 and 28215