What is the Greatest Common Factor of 21930 and 21945?

Greatest common factor (GCF) of 21930 and 21945 is 15.

GCF(21930,21945) = 15

We will now calculate the prime factors of 21930 and 21945, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21930 and 21945.

How to find the GCF of 21930 and 21945?

We will first find the prime factorization of 21930 and 21945. After we will calculate the factors of 21930 and 21945 and find the biggest common factor number .

Step-1: 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-2: Prime Factorization of 21945

Prime factors of 21945 are 3, 5, 7, 11, 19. Prime factorization of 21945 in exponential form is:

21945 = 3¹ × 5¹ × 7¹ × 11¹ × 19¹

Step-3: Factors of 21930

List of positive integer factors of 21930 that divides 21930 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

Step-4: Factors of 21945

List of positive integer factors of 21945 that divides 21930 without a remainder.

1, 3, 5, 7, 11, 15, 19, 21, 33, 35, 55, 57, 77, 95, 105, 133, 165, 209, 231, 285, 385, 399, 627, 665, 1045, 1155, 1463, 1995, 3135, 4389, 7315

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21930 and 21945. The biggest common factor number is the GCF number.
So the greatest common factor 21930 and 21945 is 15.

Also check out the Least Common Multiple of 21930 and 21945