What is the Greatest Common Factor of 21921 and 21930?

Greatest common factor (GCF) of 21921 and 21930 is 3.

GCF(21921,21930) = 3

We will now calculate the prime factors of 21921 and 21930, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21921 and 21930.

How to find the GCF of 21921 and 21930?

We will first find the prime factorization of 21921 and 21930. After we will calculate the factors of 21921 and 21930 and find the biggest common factor number .

Step-1: Prime Factorization of 21921

Prime factors of 21921 are 3, 7307. Prime factorization of 21921 in exponential form is:

21921 = 3¹ × 7307¹

Step-2: Prime Factorization of 21930

Prime factors of 21930 are 2, 3, 5, 17, 43. Prime factorization of 21930 in exponential form is:

21930 = 2¹ × 3¹ × 5¹ × 17¹ × 43¹

Step-3: Factors of 21921

List of positive integer factors of 21921 that divides 21921 without a remainder.

1, 3, 7307

Step-4: Factors of 21930

List of positive integer factors of 21930 that divides 21921 without a remainder.

1, 2, 3, 5, 6, 10, 15, 17, 30, 34, 43, 51, 85, 86, 102, 129, 170, 215, 255, 258, 430, 510, 645, 731, 1290, 1462, 2193, 3655, 4386, 7310, 10965

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21921 and 21930. The biggest common factor number is the GCF number.
So the greatest common factor 21921 and 21930 is 3.

Also check out the Least Common Multiple of 21921 and 21930