GCF for 21 and 70

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

What is the Greatest common Divisor of 21 and 70?

Answer: GCF of 21 and 70 is 7

(Seven)

Finding GCF for 21 and 70 using all factors (divisors) listing

The first method to find GCF for numbers 21 and 70 is to list all factors for both numbers and pick the highest common one:

All factors of 21: 1, 3, 7, 21

All factors of 70: 1, 2, 5, 7, 10, 14, 35, 70

So the Greatest Common Factor for 21 and 70 is 7

Finding GCF for 21 and 70 by Prime Factorization

The second method to find GCF for numbers 21 and 70 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 21: 3, 7

All Prime Factors of 70: 2, 5, 7

As we can see there is only one Prime Factor common to both numbers. It is 7

So 7 is the Greatest Common Factor of 21 and 70

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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 21 and 70? (The answer is: 7). Select the first number (e.g. '21') and the second number (e.g. '70'). 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

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

GCF Table

Number 1Number 2GCF
6702
7707
8702
9701
107010
11701
12702
13701
147014
15705
16702
17701
18702
19701
207010
21707
22702
23701
24702
25705
26702
27701
287014
29701
307010
31701
32702
33701
34702
357035

FAQ

What is the Greatest common Divisor of 21 and 70?

GCF of 21 and 70 is 7

See Also