What is the Greatest Common Factor of 21220 and 21240?

Greatest common factor (GCF) of 21220 and 21240 is 20.

GCF(21220,21240) = 20

We will now calculate the prime factors of 21220 and 21240, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21220 and 21240.

How to find the GCF of 21220 and 21240?

We will first find the prime factorization of 21220 and 21240. After we will calculate the factors of 21220 and 21240 and find the biggest common factor number .

Step-1: Prime Factorization of 21220

Prime factors of 21220 are 2, 5, 1061. Prime factorization of 21220 in exponential form is:

21220 = 2² × 5¹ × 1061¹

Step-2: Prime Factorization of 21240

Prime factors of 21240 are 2, 3, 5, 59. Prime factorization of 21240 in exponential form is:

21240 = 2³ × 3² × 5¹ × 59¹

Step-3: Factors of 21220

List of positive integer factors of 21220 that divides 21220 without a remainder.

1, 2, 4, 5, 10, 20, 1061, 2122, 4244, 5305, 10610

Step-4: Factors of 21240

List of positive integer factors of 21240 that divides 21220 without a remainder.

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 59, 60, 72, 90, 118, 120, 177, 180, 236, 295, 354, 360, 472, 531, 590, 708, 885, 1062, 1180, 1416, 1770, 2124, 2360, 2655, 3540, 4248, 5310, 7080, 10620

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21220 and 21240. The biggest common factor number is the GCF number.
So the greatest common factor 21220 and 21240 is 20.

Also check out the Least Common Multiple of 21220 and 21240