What is the Greatest Common Factor of 21390 and 21398?

Greatest common factor (GCF) of 21390 and 21398 is 2.

GCF(21390,21398) = 2

We will now calculate the prime factors of 21390 and 21398, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21390 and 21398.

How to find the GCF of 21390 and 21398?

We will first find the prime factorization of 21390 and 21398. After we will calculate the factors of 21390 and 21398 and find the biggest common factor number .

Step-1: Prime Factorization of 21390

Prime factors of 21390 are 2, 3, 5, 23, 31. Prime factorization of 21390 in exponential form is:

21390 = 2¹ × 3¹ × 5¹ × 23¹ × 31¹

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 21390

List of positive integer factors of 21390 that divides 21390 without a remainder.

1, 2, 3, 5, 6, 10, 15, 23, 30, 31, 46, 62, 69, 93, 115, 138, 155, 186, 230, 310, 345, 465, 690, 713, 930, 1426, 2139, 3565, 4278, 7130, 10695

Step-4: Factors of 21398

List of positive integer factors of 21398 that divides 21390 without a remainder.

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

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21390 and 21398. The biggest common factor number is the GCF number.
So the greatest common factor 21390 and 21398 is 2.

Also check out the Least Common Multiple of 21390 and 21398