GCF for 42 and 77

What is the Greatest common Divisor of 42 and 77?

Answer: GCF of 42 and 77 is 7

(Seven)

Finding GCF for 42 and 77 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 77 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 77: 1, 7, 11, 77

So the Greatest Common Factor for 42 and 77 is 7

Finding GCF for 42 and 77 by Prime Factorization

The second method to find GCF for numbers 42 and 77 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 77: 7, 11

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 77

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 77? (The answer is: 7). Select the first number (e.g. '42') and the second number (e.g. '77'). 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
27771
28777
29771
30771
31771
32771
3377
34771
3577
36771
37771
38771
39771
40771
41771
4277
43771
447711
45771
46771
47771
48771
4977
50771
51771
52771
53771
54771
5577
5677

FAQ

What is the Greatest common Divisor of 42 and 77?

GCF of 42 and 77 is 7