What is the Greatest Common Factor of 21615 and 21630?

Greatest common factor (GCF) of 21615 and 21630 is 15.

GCF(21615,21630) = 15

We will now calculate the prime factors of 21615 and 21630, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21615 and 21630.

How to find the GCF of 21615 and 21630?

We will first find the prime factorization of 21615 and 21630. After we will calculate the factors of 21615 and 21630 and find the biggest common factor number .

Step-1: Prime Factorization of 21615

Prime factors of 21615 are 3, 5, 11, 131. Prime factorization of 21615 in exponential form is:

21615 = 3¹ × 5¹ × 11¹ × 131¹

Step-2: Prime Factorization of 21630

Prime factors of 21630 are 2, 3, 5, 7, 103. Prime factorization of 21630 in exponential form is:

21630 = 2¹ × 3¹ × 5¹ × 7¹ × 103¹

Step-3: Factors of 21615

List of positive integer factors of 21615 that divides 21615 without a remainder.

1, 3, 5, 11, 15, 33, 55, 131, 165, 393, 655, 1441, 1965, 4323, 7205

Step-4: Factors of 21630

List of positive integer factors of 21630 that divides 21615 without a remainder.

1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 103, 105, 206, 210, 309, 515, 618, 721, 1030, 1442, 1545, 2163, 3090, 3605, 4326, 7210, 10815

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21615 and 21630. The biggest common factor number is the GCF number.
So the greatest common factor 21615 and 21630 is 15.

Also check out the Least Common Multiple of 21615 and 21630