GCF for 20 and 80

What is the Greatest common Divisor of 20 and 80?

Answer: GCF of 20 and 80 is 20

(Twenty)

Finding GCF for 20 and 80 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 80 is to list all factors for both numbers and pick the highest common one:

All factors of 20: 1, 2, 4, 5, 10, 20

All factors of 80: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

So the Greatest Common Factor for 20 and 80 is 20

Finding GCF for 20 and 80 by Prime Factorization

The second method to find GCF for numbers 20 and 80 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 20: 2, 2, 5

All Prime Factors of 80: 2, 2, 2, 2, 5

As we can see there are Prime Factors common to both numbers: 2, 2, 5

Now we need to multiply them to find GCF: 2 × 2 × 5 = 20

See Also

GCF Table

Number 1Number 2GCF
5805
6802
7801
8808
9801
108010
11801
1280
13801
14802
1580
1680
17801
18802
19801
2080
21801
22802
23801
2480
2580
26802
27801
2880
29801
3080
31801
3280
33801
34802

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest common Divisor of 20 and 80? (The answer is: 20). Select the first number (e.g. '20') and the second number (e.g. '80'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest common Divisor of 20 and 80?

GCF of 20 and 80 is 20