GCF for 28 and 49

What is the Greatest common Divisor of 28 and 49?

Answer: GCF of 28 and 49 is 7

(Seven)

Finding GCF for 28 and 49 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 49 is to list all factors for both numbers and pick the highest common one:

All factors of 28: 1, 2, 4, 7, 14, 28

All factors of 49: 1, 7, 49

So the Greatest Common Factor for 28 and 49 is 7

Finding GCF for 28 and 49 by Prime Factorization

The second method to find GCF for numbers 28 and 49 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 28: 2, 2, 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 28 and 49

See Also

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 28 and 49? (The answer is: 7). Select the first number (e.g. '28') 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

GCF Table

Number 1Number 2GCF
13491
1449
15491
1649
17491
18491
19491
20491
2149
22491
23491
24491
2549
26491
2749
2849
29491
3049
31491
3249
33491
34491
3549
36491
37491
38491
39491
40491
41491
4249

FAQ

What is the Greatest common Divisor of 28 and 49?

GCF of 28 and 49 is 7