What is the greatest common factor of 820?

Answer 1

There is neither a greatest common factor nor common factors of a single number, such as 820 because there cannot be any form of common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common. The greatest common factor is the largest factor that all the numbers being compared have in common. Thus, since there are not two or more numbers to compare, there are neither common factors nor a greatest common factor.

The factors of 820 are 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410, and 820.

The prime factors of 820 are 2, 2, 5, and 41.

Examples:

The common factors of 16 and 820 are 1, 2, and 4; the greatest common factor is 4.

The common factor of 21 and 820 is 1; the greatest common factor is 1.

The common factors of 615 and 820 are 1, 5, 41, and 205; the greatest common factor is 205.