GCF for 40 and 45

What is the Greatest common Divisor of 40 and 45?

Answer: GCF of 40 and 45 is 5

(Five)

Finding GCF for 40 and 45 using all factors (divisors) listing

The first method to find GCF for numbers 40 and 45 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 45: 1, 3, 5, 9, 15, 45

So the Greatest Common Factor for 40 and 45 is 5

Finding GCF for 40 and 45 by Prime Factorization

The second method to find GCF for numbers 40 and 45 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 45: 3, 3, 5

As we can see there is only one Prime Factor common to both numbers. It is 5

So 5 is the Greatest Common Factor of 40 and 45

GCF Table

Number 1Number 2GCF
2545
2645
2745
2845
2945
3045
31451
3245
33453
34451
3545
3645
37451
38451
3945
4045
41451
4245
43451
44451
454545
46451
47451
48453
49451
50455
51453
52451
53451
54459

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 45? (The answer is: 5). Select the first number (e.g. '40') and the second number (e.g. '45'). 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 45?

GCF of 40 and 45 is 5