GCF for 78 and 91

What is the Greatest common Divisor of 78 and 91?

Answer: GCF of 78 and 91 is 13

(Thirteen)

Finding GCF for 78 and 91 using all factors (divisors) listing

The first method to find GCF for numbers 78 and 91 is to list all factors for both numbers and pick the highest common one:

All factors of 78: 1, 2, 3, 6, 13, 26, 39, 78

All factors of 91: 1, 7, 13, 91

So the Greatest Common Factor for 78 and 91 is 13

Finding GCF for 78 and 91 by Prime Factorization

The second method to find GCF for numbers 78 and 91 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 78: 2, 3, 13

All Prime Factors of 91: 7, 13

As we can see there is only one Prime Factor common to both numbers. It is 13

So 13 is the Greatest Common Factor of 78 and 91

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 78 and 91? (The answer is: 13). Select the first number (e.g. '78') and the second number (e.g. '91'). 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
6391
64911
6591
66911
67911
68911
69911
70917
71911
72911
73911
74911
75911
76911
7791
7891
79911
80911
81911
82911
83911
8491
85911
86911
87911
88911
89911
90911
919191
92911

FAQ

What is the Greatest common Divisor of 78 and 91?

GCF of 78 and 91 is 13