# Greatest Common Factor of 81 and 84

Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 81, 84 i.e. 3 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 81 and 84 is 3.

GCF(81,84) = 3

## GCF of 81 and 84

Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;

GCF of:
and

### Greatest Common Factor of 81 and 84 by Prime factorization method

Prime Factorization of 81

 3 81 3 27 3 9 3 3 1

Prime factors of 81 are 3. Prime factorization of 81 in exponential form is:

81 = 34

Prime Factorization of 84

 2 84 2 42 3 21 7 7 1

Prime factors of 84 are 2.Prime factorization of 84 in exponential form is:

84 = 22×31×71

∴ So by taking common prime factors GCF of 81 and 84 is 3

### Greatest Common Factor of 81 and 84 by matching factors method

Factors of 81

List of positive integer factors of 81 that divides 81 without a remainder.

1,3,9,27,81

Factors of 84

List of positive integer factors of 84 that divides 84 without a remainder.

1,2,3,4,6,7,12,14,21,28,42,84

Greatest Common Factor

We found the factors and prime factorization of 81 and 84. The biggest common factor number is the GCF number.
So the greatest common factor 81 and 84 is 3.

Also check out the Least Common Multiple of 81 and 84

### Properties of GCF 81 and 84

(i) The GCF of 81 and 84 is associative

GCF of 81 and 84 = GCF of 84 and 81

### Frequently Asked Questions on GCF of 81 and 84

1. What is the GCF of 81 and 84?

Answer: GCF of 81 and 84 is 3.

2. What are the Factors of 81?

Answer: Factors of 81 are 1, 3, 9, 27, 81. There are 5 integers that are factors of 81. The greatest factor of 81 is 81.

3. What are the Factors of 84?

Answer: Factors of 84 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84. There are 12 integers that are factors of 84. The greatest factor of 84 is 84.

4. How to Find the GCF of 81 and 84?

Answer:

Greatest Common Factor of 81 and 84 = 3

Step 1: Find the prime factorization of 81

81 = 3 x 3 x 3 x 3

Step 2: Find the prime factorization of 84

84 = 2 x 2 x 3 x 7

Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:

GCF = 3

Step 4: Therefore, the greatest common factor of 81 and 84 is 3