GCF for 45 and 90

What is the Greatest common Divisor of 45 and 90?

Answer: GCF of 45 and 90 is 45

(Forty-five)

Finding GCF for 45 and 90 using all factors (divisors) listing

The first method to find GCF for numbers 45 and 90 is to list all factors for both numbers and pick the highest common one:

All factors of 45: 1, 3, 5, 9, 15, 45

All factors of 90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90

So the Greatest Common Factor for 45 and 90 is 45

Finding GCF for 45 and 90 by Prime Factorization

The second method to find GCF for numbers 45 and 90 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 45: 3, 3, 5

All Prime Factors of 90: 2, 3, 3, 5

As we can see there are Prime Factors common to both numbers: 3, 3, 5

Now we need to multiply them to find GCF: 3 × 3 × 5 = 45

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 45 and 90? (The answer is: 45). Select the first number (e.g. '45') and the second number (e.g. '90'). 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
3090
31901
3290
33903
34902
3590
3690
37901
38902
39903
4090
41901
4290
43901
44902
4590
46902
47901
4890
49901
5090
51903
52902
53901
5490
55905
56902
57903
58902
59901

FAQ

What is the Greatest common Divisor of 45 and 90?

GCF of 45 and 90 is 45