What is the Greatest Common Factor of 20640 and 20656?

Greatest common factor (GCF) of 20640 and 20656 is 16.

GCF(20640,20656) = 16

We will now calculate the prime factors of 20640 and 20656, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20640 and 20656.

How to find the GCF of 20640 and 20656?

We will first find the prime factorization of 20640 and 20656. After we will calculate the factors of 20640 and 20656 and find the biggest common factor number .

Step-1: Prime Factorization of 20640

Prime factors of 20640 are 2, 3, 5, 43. Prime factorization of 20640 in exponential form is:

20640 = 2⁵ × 3¹ × 5¹ × 43¹

Step-2: Prime Factorization of 20656

Prime factors of 20656 are 2, 1291. Prime factorization of 20656 in exponential form is:

20656 = 2⁴ × 1291¹

Step-3: Factors of 20640

List of positive integer factors of 20640 that divides 20640 without a remainder.

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 43, 48, 60, 80, 86, 96, 120, 129, 160, 172, 215, 240, 258, 344, 430, 480, 516, 645, 688, 860, 1032, 1290, 1376, 1720, 2064, 2580, 3440, 4128, 5160, 6880, 10320

Step-4: Factors of 20656

List of positive integer factors of 20656 that divides 20640 without a remainder.

1, 2, 4, 8, 16, 1291, 2582, 5164, 10328

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20640 and 20656. The biggest common factor number is the GCF number.
So the greatest common factor 20640 and 20656 is 16.

Also check out the Least Common Multiple of 20640 and 20656