GCF for 42 and 51

What is the Greatest Common Factor of 42 and 51?

Answer: GCF of 42 and 51 is 3

(Three)

Finding GCF for 42 and 51 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 51 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 51: 1, 3, 17, 51

So the Greatest Common Factor for 42 and 51 is 3

Finding GCF for 42 and 51 by Prime Factorization

The second method to find GCF for numbers 42 and 51 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 51: 3, 17

As we can see there is only one Prime Factor common to both numbers. It is 3

So 3 is the Greatest Common Factor of 42 and 51

Related Calculations

GCF Table

Number 1Number 2GCF
27513
28511
29511
30513
31511
32511
33513
3451
35511
36513
37511
38511
39513
40511
41511
42513
43511
44511
45513
46511
47511
48513
49511
50511
515151
52511
53511
54513
55511
56511

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 51? (The answer is: 3). Select the first number (e.g. '42') and the second number (e.g. '51'). 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 51?

GCF of 42 and 51 is 3