# Greatest Common Factor of 8 and 20

Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 8, 20 i.e. 4 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 8 and 20 is 4.

GCF(8,20) = 4

## GCF of 8 and 20

Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;

GCF of:
and

### Greatest Common Factor of 8 and 20 by Prime factorization method

Prime Factorization of 8

 2 8 2 4 2 2 1

Prime factors of 8 are 2. Prime factorization of 8 in exponential form is:

8 = 23

Prime Factorization of 20

 2 20 2 10 5 5 1

Prime factors of 20 are 2.Prime factorization of 20 in exponential form is:

20 = 22×51

∴ So by taking common prime factors GCF of 8 and 20 is 4

### Greatest Common Factor of 8 and 20 by matching factors method

Factors of 8

List of positive integer factors of 8 that divides 8 without a remainder.

1,2,4,8

Factors of 20

List of positive integer factors of 20 that divides 20 without a remainder.

1,2,4,5,10,20

Greatest Common Factor

We found the factors and prime factorization of 8 and 20. The biggest common factor number is the GCF number.
So the greatest common factor 8 and 20 is 4.

Also check out the Least Common Multiple of 8 and 20

### Properties of GCF 8 and 20

(i) The GCF of 8 and 20 is associative

GCF of 8 and 20 = GCF of 20 and 8

### Frequently Asked Questions on GCF of 8 and 20

1. What is the GCF of 8 and 20?

Answer: GCF of 8 and 20 is 4.

2. What are the Factors of 8?

Answer: Factors of 8 are 1, 2, 4, 8. There are 4 integers that are factors of 8. The greatest factor of 8 is 8.

3. What are the Factors of 20?

Answer: Factors of 20 are 1, 2, 4, 5, 10, 20. There are 6 integers that are factors of 20. The greatest factor of 20 is 20.

4. How to Find the GCF of 8 and 20?

Greatest Common Factor of 8 and 20 = 4

Step 1: Find the prime factorization of 8

8 = 2 x 2 x 2

Step 2: Find the prime factorization of 20

20 = 2 x 2 x 5

Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:

GCF = 2 x 2 = 4

Step 4: Therefore, the greatest common factor of 8 and 20 is 4