What is the Greatest Common Factor of 21385 and 21398?

Greatest common factor (GCF) of 21385 and 21398 is 13.

GCF(21385,21398) = 13

We will now calculate the prime factors of 21385 and 21398, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21385 and 21398.

How to find the GCF of 21385 and 21398?

We will first find the prime factorization of 21385 and 21398. After we will calculate the factors of 21385 and 21398 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 21398

Prime factors of 21398 are 2, 13, 823. Prime factorization of 21398 in exponential form is:

21398 = 2¹ × 13¹ × 823¹

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 21398

List of positive integer factors of 21398 that divides 21385 without a remainder.

1, 2, 13, 26, 823, 1646, 10699

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21385 and 21398. The biggest common factor number is the GCF number.
So the greatest common factor 21385 and 21398 is 13.

Also check out the Least Common Multiple of 21385 and 21398