What is the Greatest Common Factor of 21405 and 21421?

Greatest common factor (GCF) of 21405 and 21421 is 1.

GCF(21405,21421) = 1

We will now calculate the prime factors of 21405 and 21421, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21405 and 21421.

How to find the GCF of 21405 and 21421?

We will first find the prime factorization of 21405 and 21421. After we will calculate the factors of 21405 and 21421 and find the biggest common factor number .

Step-1: Prime Factorization of 21405

Prime factors of 21405 are 3, 5, 1427. Prime factorization of 21405 in exponential form is:

21405 = 3¹ × 5¹ × 1427¹

Step-2: Prime Factorization of 21421

Prime factors of 21421 are 31, 691. Prime factorization of 21421 in exponential form is:

21421 = 31¹ × 691¹

Step-3: Factors of 21405

List of positive integer factors of 21405 that divides 21405 without a remainder.

1, 3, 5, 15, 1427, 4281, 7135

Step-4: Factors of 21421

List of positive integer factors of 21421 that divides 21405 without a remainder.

1, 31, 691

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21405 and 21421. The biggest common factor number is the GCF number.
So the greatest common factor 21405 and 21421 is 1.

Also check out the Least Common Multiple of 21405 and 21421