GCF for 42 and 49

What is the Greatest common Divisor of 42 and 49?

Answer: GCF of 42 and 49 is 7

(Seven)

Finding GCF for 42 and 49 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 49 is to list all factors for both numbers and pick the highest common one:

All factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

All factors of 49: 1, 7, 49

So the Greatest Common Factor for 42 and 49 is 7

Finding GCF for 42 and 49 by Prime Factorization

The second method to find GCF for numbers 42 and 49 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 42: 2, 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 42 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 42 and 49? (The answer is: 7). Select the first number (e.g. '42') 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
2749
2849
29491
30491
31491
3249
33491
34491
3549
3649
37491
38491
39491
40491
41491
4249
43491
44491
4549
46491
47491
4849
494949
50491
51491
52491
53491
54491
55491
56497

FAQ

What is the Greatest common Divisor of 42 and 49?

GCF of 42 and 49 is 7