GCF of 81 and 117 (Greatest Common Factor)

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 81 and 117?

Answer

GCF of 81 and 117 is
9

(Nine)

Finding GCF for 81 and 117 using all factors (divisors) listing

The first method to find GCF for numbers 81 and 117 is to list all factors for both numbers and pick the highest common one:

All factors of 81: 1, 3, 9, 27, 81

All factors of 117: 1, 3, 9, 13, 39, 117

So the Greatest Common Factor for 81 and 117 is 9

Finding GCF for 81 and 117 by Prime Factorization

The second method to find GCF for numbers 81 and 117 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 81: 3, 3, 3, 3

All Prime Factors of 117: 3, 3, 13

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 81 and 117? (The answer is: 9). Select the first number (e.g. '81') and the second number (e.g. '117'). 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
811023
811031
811041
811053
811061
811071
8110827
811091
811101
811113
811121
811131
811143
811151
811161
811179
811181
811191
811203
811211
811221
811233
811241
811251
811269
811271
811281
811293
811301
811311

FAQ

What is the Greatest Common Divisor of 81 and 117?

GCF of 81 and 117 is 9

How to find the GCF of 81 and 117?

You can find the GCF of 81 and 117 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 81 and 117 is 9.

What prime factors do 81 and 117 share?

The prime factorizations of 81 and 117 have 3 × 3 in common, and multiplying those shared primes gives 9 — exactly the greatest common factor.

How does the GCF reduce the fraction 81/117?

Divide the numerator and the denominator by the GCF 9: 81 ÷ 9 = 9 and 117 ÷ 9 = 13. So 81/117 in lowest terms is 9/13.

See Also