What is the Greatest Common Factor of 20605 and 20620?

Greatest common factor (GCF) of 20605 and 20620 is 5.

GCF(20605,20620) = 5

We will now calculate the prime factors of 20605 and 20620, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20605 and 20620.

How to find the GCF of 20605 and 20620?

We will first find the prime factorization of 20605 and 20620. After we will calculate the factors of 20605 and 20620 and find the biggest common factor number .

Step-1: Prime Factorization of 20605

Prime factors of 20605 are 5, 13, 317. Prime factorization of 20605 in exponential form is:

20605 = 5¹ × 13¹ × 317¹

Step-2: Prime Factorization of 20620

Prime factors of 20620 are 2, 5, 1031. Prime factorization of 20620 in exponential form is:

20620 = 2² × 5¹ × 1031¹

Step-3: Factors of 20605

List of positive integer factors of 20605 that divides 20605 without a remainder.

1, 5, 13, 65, 317, 1585, 4121

Step-4: Factors of 20620

List of positive integer factors of 20620 that divides 20605 without a remainder.

1, 2, 4, 5, 10, 20, 1031, 2062, 4124, 5155, 10310

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20605 and 20620. The biggest common factor number is the GCF number.
So the greatest common factor 20605 and 20620 is 5.

Also check out the Least Common Multiple of 20605 and 20620