What is the Greatest Common Factor of 21385 and 21399?

Greatest common factor (GCF) of 21385 and 21399 is 7.

GCF(21385,21399) = 7

We will now calculate the prime factors of 21385 and 21399, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21385 and 21399.

How to find the GCF of 21385 and 21399?

We will first find the prime factorization of 21385 and 21399. After we will calculate the factors of 21385 and 21399 and find the biggest common factor number .

Step-1: Prime Factorization of 21385

Prime factors of 21385 are 5, 7, 13, 47. Prime factorization of 21385 in exponential form is:

21385 = 5¹ × 7¹ × 13¹ × 47¹

Step-2: Prime Factorization of 21399

Prime factors of 21399 are 3, 7, 1019. Prime factorization of 21399 in exponential form is:

21399 = 3¹ × 7¹ × 1019¹

Step-3: Factors of 21385

List of positive integer factors of 21385 that divides 21385 without a remainder.

1, 5, 7, 13, 35, 47, 65, 91, 235, 329, 455, 611, 1645, 3055, 4277

Step-4: Factors of 21399

List of positive integer factors of 21399 that divides 21385 without a remainder.

1, 3, 7, 21, 1019, 3057, 7133

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21385 and 21399. The biggest common factor number is the GCF number.
So the greatest common factor 21385 and 21399 is 7.

Also check out the Least Common Multiple of 21385 and 21399