What is the Greatest Common Factor of 21780 and 21791?

Greatest common factor (GCF) of 21780 and 21791 is 11.

GCF(21780,21791) = 11

We will now calculate the prime factors of 21780 and 21791, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21780 and 21791.

How to find the GCF of 21780 and 21791?

We will first find the prime factorization of 21780 and 21791. After we will calculate the factors of 21780 and 21791 and find the biggest common factor number .

Step-1: Prime Factorization of 21780

Prime factors of 21780 are 2, 3, 5, 11. Prime factorization of 21780 in exponential form is:

21780 = 2² × 3² × 5¹ × 11²

Step-2: Prime Factorization of 21791

Prime factors of 21791 are 7, 11, 283. Prime factorization of 21791 in exponential form is:

21791 = 7¹ × 11¹ × 283¹

Step-3: Factors of 21780

List of positive integer factors of 21780 that divides 21780 without a remainder.

1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 15, 18, 20, 22, 30, 33, 36, 44, 45, 55, 60, 66, 90, 99, 110, 121, 132, 165, 180, 198, 220, 242, 330, 363, 396, 484, 495, 605, 660, 726, 990, 1089, 1210, 1452, 1815, 1980, 2178, 2420, 3630, 4356, 5445, 7260, 10890

Step-4: Factors of 21791

List of positive integer factors of 21791 that divides 21780 without a remainder.

1, 7, 11, 77, 283, 1981, 3113

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21780 and 21791. The biggest common factor number is the GCF number.
So the greatest common factor 21780 and 21791 is 11.

Also check out the Least Common Multiple of 21780 and 21791