What is the Greatest Common Factor of 21285 and 21289?

Greatest common factor (GCF) of 21285 and 21289 is 1.

GCF(21285,21289) = 1

We will now calculate the prime factors of 21285 and 21289, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21285 and 21289.

How to find the GCF of 21285 and 21289?

We will first find the prime factorization of 21285 and 21289. After we will calculate the factors of 21285 and 21289 and find the biggest common factor number .

Step-1: Prime Factorization of 21285

Prime factors of 21285 are 3, 5, 11, 43. Prime factorization of 21285 in exponential form is:

21285 = 3² × 5¹ × 11¹ × 43¹

Step-2: Prime Factorization of 21289

Prime factors of 21289 are 61, 349. Prime factorization of 21289 in exponential form is:

21289 = 61¹ × 349¹

Step-3: Factors of 21285

List of positive integer factors of 21285 that divides 21285 without a remainder.

1, 3, 5, 9, 11, 15, 33, 43, 45, 55, 99, 129, 165, 215, 387, 473, 495, 645, 1419, 1935, 2365, 4257, 7095

Step-4: Factors of 21289

List of positive integer factors of 21289 that divides 21285 without a remainder.

1, 61, 349

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21285 and 21289. The biggest common factor number is the GCF number.
So the greatest common factor 21285 and 21289 is 1.

Also check out the Least Common Multiple of 21285 and 21289