What is the Greatest Common Factor of 21780 and 21784?

Greatest common factor (GCF) of 21780 and 21784 is 4.

GCF(21780,21784) = 4

We will now calculate the prime factors of 21780 and 21784, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21780 and 21784.

How to find the GCF of 21780 and 21784?

We will first find the prime factorization of 21780 and 21784. After we will calculate the factors of 21780 and 21784 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 21784

Prime factors of 21784 are 2, 7, 389. Prime factorization of 21784 in exponential form is:

21784 = 2³ × 7¹ × 389¹

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 21784

List of positive integer factors of 21784 that divides 21780 without a remainder.

1, 2, 4, 7, 8, 14, 28, 56, 389, 778, 1556, 2723, 3112, 5446, 10892

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21780 and 21784. The biggest common factor number is the GCF number.
So the greatest common factor 21780 and 21784 is 4.

Also check out the Least Common Multiple of 21780 and 21784