GCF of 45 and 108 (Greatest Common Factor)

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 45 and 108?

Answer

GCF of 45 and 108 is
9

(Nine)

Finding GCF for 45 and 108 using all factors (divisors) listing

The first method to find GCF for numbers 45 and 108 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 108: 1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, 108

So the Greatest Common Factor for 45 and 108 is 9

Finding GCF for 45 and 108 by Prime Factorization

The second method to find GCF for numbers 45 and 108 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 108: 2, 2, 3, 3, 3

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

Now we need to multiply them to find GCF: 3 × 3 = 9

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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 108? (The answer is: 9). Select the first number (e.g. '45') and the second number (e.g. '108'). 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.
"Greatest Common Factor" Calculator
Greatest Common Factor of
and

GCF Table

Number 1Number 2GCF
451515
453015
45483
45491
45505
45513
45521
45549
45555
45561
456015
45639
45655
45705
45729
457515
45819
45843
459045
45999
451005
4510515
451089
4512015
4513545
4515015
4518045

FAQ

What is the Greatest Common Divisor of 45 and 108?

GCF of 45 and 108 is 9

How to find the GCF of 45 and 108?

You can find the GCF of 45 and 108 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 45 and 108 is 9.

What prime factors do 45 and 108 share?

The prime factorizations of 45 and 108 have 3 × 3 in common, and multiplying those shared primes gives 9 — exactly the greatest common factor.

How does the GCF reduce the fraction 45/108?

Divide the numerator and the denominator by the GCF 9: 45 ÷ 9 = 5 and 108 ÷ 9 = 12. So 45/108 in lowest terms is 5/12.

See Also