What is the Greatest Common Factor of 81920 and 81940?

Greatest common factor (GCF) of 81920 and 81940 is 20.

GCF(81920,81940) = 20

We will now calculate the prime factors of 81920 and 81940, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 81920 and 81940.

How to find the GCF of 81920 and 81940?

We will first find the prime factorization of 81920 and 81940. After we will calculate the factors of 81920 and 81940 and find the biggest common factor number .

Step-1: Prime Factorization of 81920

Prime factors of 81920 are 2, 5. Prime factorization of 81920 in exponential form is:

81920 = 2¹⁴ × 5¹

Step-2: Prime Factorization of 81940

Prime factors of 81940 are 2, 5, 17, 241. Prime factorization of 81940 in exponential form is:

81940 = 2² × 5¹ × 17¹ × 241¹

Step-3: Factors of 81920

List of positive integer factors of 81920 that divides 81920 without a remainder.

1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 256, 320, 512, 640, 1024, 1280, 2048, 2560, 4096, 5120, 8192, 10240, 16384, 20480, 40960

Step-4: Factors of 81940

List of positive integer factors of 81940 that divides 81920 without a remainder.

1, 2, 4, 5, 10, 17, 20, 34, 68, 85, 170, 241, 340, 482, 964, 1205, 2410, 4097, 4820, 8194, 16388, 20485, 40970

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 81920 and 81940. The biggest common factor number is the GCF number.
So the greatest common factor 81920 and 81940 is 20.

Also check out the Least Common Multiple of 81920 and 81940