What is the Greatest Common Factor of 21663 and 21681?

Greatest common factor (GCF) of 21663 and 21681 is 9.

GCF(21663,21681) = 9

We will now calculate the prime factors of 21663 and 21681, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21663 and 21681.

How to find the GCF of 21663 and 21681?

We will first find the prime factorization of 21663 and 21681. After we will calculate the factors of 21663 and 21681 and find the biggest common factor number .

Step-1: Prime Factorization of 21663

Prime factors of 21663 are 3, 29, 83. Prime factorization of 21663 in exponential form is:

21663 = 3² × 29¹ × 83¹

Step-2: Prime Factorization of 21681

Prime factors of 21681 are 3, 11, 73. Prime factorization of 21681 in exponential form is:

21681 = 3³ × 11¹ × 73¹

Step-3: Factors of 21663

List of positive integer factors of 21663 that divides 21663 without a remainder.

1, 3, 9, 29, 83, 87, 249, 261, 747, 2407, 7221

Step-4: Factors of 21681

List of positive integer factors of 21681 that divides 21663 without a remainder.

1, 3, 9, 11, 27, 33, 73, 99, 219, 297, 657, 803, 1971, 2409, 7227

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21663 and 21681. The biggest common factor number is the GCF number.
So the greatest common factor 21663 and 21681 is 9.

Also check out the Least Common Multiple of 21663 and 21681