What is the Greatest Common Factor of 21640 and 21660?

Greatest common factor (GCF) of 21640 and 21660 is 20.

GCF(21640,21660) = 20

We will now calculate the prime factors of 21640 and 21660, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21640 and 21660.

How to find the GCF of 21640 and 21660?

We will first find the prime factorization of 21640 and 21660. After we will calculate the factors of 21640 and 21660 and find the biggest common factor number .

Step-1: Prime Factorization of 21640

Prime factors of 21640 are 2, 5, 541. Prime factorization of 21640 in exponential form is:

21640 = 2³ × 5¹ × 541¹

Step-2: Prime Factorization of 21660

Prime factors of 21660 are 2, 3, 5, 19. Prime factorization of 21660 in exponential form is:

21660 = 2² × 3¹ × 5¹ × 19²

Step-3: Factors of 21640

List of positive integer factors of 21640 that divides 21640 without a remainder.

1, 2, 4, 5, 8, 10, 20, 40, 541, 1082, 2164, 2705, 4328, 5410, 10820

Step-4: Factors of 21660

List of positive integer factors of 21660 that divides 21640 without a remainder.

1, 2, 3, 4, 5, 6, 10, 12, 15, 19, 20, 30, 38, 57, 60, 76, 95, 114, 190, 228, 285, 361, 380, 570, 722, 1083, 1140, 1444, 1805, 2166, 3610, 4332, 5415, 7220, 10830

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21640 and 21660. The biggest common factor number is the GCF number.
So the greatest common factor 21640 and 21660 is 20.

Also check out the Least Common Multiple of 21640 and 21660