GCF for 42 and 78

What is the Greatest common Divisor of 42 and 78?

Answer: GCF of 42 and 78 is 6

(Six)

Finding GCF for 42 and 78 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 78 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 78: 1, 2, 3, 6, 13, 26, 39, 78

So the Greatest Common Factor for 42 and 78 is 6

Finding GCF for 42 and 78 by Prime Factorization

The second method to find GCF for numbers 42 and 78 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 78: 2, 3, 13

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

Now we need to multiply them to find GCF: 2 × 3 = 6

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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 42 and 78? (The answer is: 6). Select the first number (e.g. '42') and the second number (e.g. '78'). 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
27783
28782
29781
3078
31781
32782
33783
34782
35781
3678
37781
38782
3978
40782
41781
4278
43781
44782
45783
46782
47781
4878
49781
50782
51783
5278
53781
5478
55781
56782

FAQ

What is the Greatest common Divisor of 42 and 78?

GCF of 42 and 78 is 6