What is the Greatest Common Factor of 21605 and 21621?

Greatest common factor (GCF) of 21605 and 21621 is 1.

GCF(21605,21621) = 1

We will now calculate the prime factors of 21605 and 21621, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21605 and 21621.

How to find the GCF of 21605 and 21621?

We will first find the prime factorization of 21605 and 21621. After we will calculate the factors of 21605 and 21621 and find the biggest common factor number .

Step-1: Prime Factorization of 21605

Prime factors of 21605 are 5, 29, 149. Prime factorization of 21605 in exponential form is:

21605 = 5¹ × 29¹ × 149¹

Step-2: Prime Factorization of 21621

Prime factors of 21621 are 3, 7207. Prime factorization of 21621 in exponential form is:

21621 = 3¹ × 7207¹

Step-3: Factors of 21605

List of positive integer factors of 21605 that divides 21605 without a remainder.

1, 5, 29, 145, 149, 745, 4321

Step-4: Factors of 21621

List of positive integer factors of 21621 that divides 21605 without a remainder.

1, 3, 7207

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21605 and 21621. The biggest common factor number is the GCF number.
So the greatest common factor 21605 and 21621 is 1.

Also check out the Least Common Multiple of 21605 and 21621