What is the Greatest Common Factor of 20855 and 20870?

Greatest common factor (GCF) of 20855 and 20870 is 5.

GCF(20855,20870) = 5

We will now calculate the prime factors of 20855 and 20870, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20855 and 20870.

How to find the GCF of 20855 and 20870?

We will first find the prime factorization of 20855 and 20870. After we will calculate the factors of 20855 and 20870 and find the biggest common factor number .

Step-1: Prime Factorization of 20855

Prime factors of 20855 are 5, 43, 97. Prime factorization of 20855 in exponential form is:

20855 = 5¹ × 43¹ × 97¹

Step-2: Prime Factorization of 20870

Prime factors of 20870 are 2, 5, 2087. Prime factorization of 20870 in exponential form is:

20870 = 2¹ × 5¹ × 2087¹

Step-3: Factors of 20855

List of positive integer factors of 20855 that divides 20855 without a remainder.

1, 5, 43, 97, 215, 485, 4171

Step-4: Factors of 20870

List of positive integer factors of 20870 that divides 20855 without a remainder.

1, 2, 5, 10, 2087, 4174, 10435

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20855 and 20870. The biggest common factor number is the GCF number.
So the greatest common factor 20855 and 20870 is 5.

Also check out the Least Common Multiple of 20855 and 20870