GCF for 42 and 84

What is the Greatest Common Factor of 42 and 84?

Answer: GCF of 42 and 84 is 42

(Forty-two)

Finding GCF for 42 and 84 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 84 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 84: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84

So the Greatest Common Factor for 42 and 84 is 42

Finding GCF for 42 and 84 by Prime Factorization

The second method to find GCF for numbers 42 and 84 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 84: 2, 2, 3, 7

As we can see there are Prime Factors common to both numbers: 2, 3, 7

Now we need to multiply them to find GCF: 2 Γ— 3 Γ— 7 = 42

GCF Table

Number 1Number 2GCF
27843
2884
29841
3084
31841
3284
33843
34842
3584
3684
37841
38842
39843
4084
41841
4284
43841
44844
45843
46842
47841
4884
4984
50842
51843
52844
53841
5484
55841
5684

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 Factor of 42 and 84? (The answer is: 42). Select the first number (e.g. '42') and the second number (e.g. '84'). 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 Factor of 42 and 84?

GCF of 42 and 84 is 42