What is the Greatest Common Factor of 21440 and 21455?

Greatest common factor (GCF) of 21440 and 21455 is 5.

GCF(21440,21455) = 5

We will now calculate the prime factors of 21440 and 21455, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21440 and 21455.

How to find the GCF of 21440 and 21455?

We will first find the prime factorization of 21440 and 21455. After we will calculate the factors of 21440 and 21455 and find the biggest common factor number .

Step-1: Prime Factorization of 21440

Prime factors of 21440 are 2, 5, 67. Prime factorization of 21440 in exponential form is:

21440 = 2⁶ × 5¹ × 67¹

Step-2: Prime Factorization of 21455

Prime factors of 21455 are 5, 7, 613. Prime factorization of 21455 in exponential form is:

21455 = 5¹ × 7¹ × 613¹

Step-3: Factors of 21440

List of positive integer factors of 21440 that divides 21440 without a remainder.

1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 67, 80, 134, 160, 268, 320, 335, 536, 670, 1072, 1340, 2144, 2680, 4288, 5360, 10720

Step-4: Factors of 21455

List of positive integer factors of 21455 that divides 21440 without a remainder.

1, 5, 7, 35, 613, 3065, 4291

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21440 and 21455. The biggest common factor number is the GCF number.
So the greatest common factor 21440 and 21455 is 5.

Also check out the Least Common Multiple of 21440 and 21455