GCF for 21 and 49

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

What is the Greatest common Divisor of 21 and 49?

Answer: GCF of 21 and 49 is 7

(Seven)

Finding GCF for 21 and 49 using all factors (divisors) listing

The first method to find GCF for numbers 21 and 49 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 49: 1, 7, 49

So the Greatest Common Factor for 21 and 49 is 7

Finding GCF for 21 and 49 by Prime Factorization

The second method to find GCF for numbers 21 and 49 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 49: 7, 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 49

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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 49? (The answer is: 7). Select the first number (e.g. '21') and the second number (e.g. '49'). 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
6491
7497
8491
9491
10491
11491
12491
13491
14497
15491
16491
17491
18491
19491
20491
21497
22491
23491
24491
25491
26491
27491
28497
29491
30491
31491
32491
33491
34491
35497

FAQ

What is the Greatest common Divisor of 21 and 49?

GCF of 21 and 49 is 7

See Also