GCF for 40 and 42

What is the Greatest common Divisor of 40 and 42?

Answer: GCF of 40 and 42 is 2

(Two)

Finding GCF for 40 and 42 using all factors (divisors) listing

The first method to find GCF for numbers 40 and 42 is to list all factors for both numbers and pick the highest common one:

All factors of 40: 1, 2, 4, 5, 8, 10, 20, 40

All factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

So the Greatest Common Factor for 40 and 42 is 2

Finding GCF for 40 and 42 by Prime Factorization

The second method to find GCF for numbers 40 and 42 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 40: 2, 2, 2, 5

All Prime Factors of 42: 2, 3, 7

As we can see there is only one Prime Factor common to both numbers. It is 2

So 2 is the Greatest Common Factor of 40 and 42

Related Calculations

See Also

GCF Table

Number 1Number 2GCF
2542
2642
2742
2842
29421
3042
31421
3242
33423
34422
3542
3642
37421
3842
3942
4042
41421
424242
43421
44422
45423
46422
47421
48426
49427
50422
51423
52422
53421
54426

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 40 and 42? (The answer is: 2). Select the first number (e.g. '40') and the second number (e.g. '42'). 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 Divisor of 40 and 42?

GCF of 40 and 42 is 2