Greatest Common Factor of 78 and 81

Created By : Jatin Gogia

Reviewed By : Rajasekhar Valipishetty

Last Updated : Apr 06, 2023

Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 78, 81 i.e. 3 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 78 and 81 is 3.

GCF(78,81) = 3

GCF of 78 and 81

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

GCF of:
and

Greatest Common Factor of 78 and 81

GCF of 78 and 81 is 3

Prime Factorization of 78


2 78
3 39
13 13
1

Prime factors of 78 are 2,3,13. Prime factorization of 78 in exponential form is:

78 = 21×31×131

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

∴ So by taking common prime factors GCF of 78 and 81 is 3

Greatest Common Factor of 78 and 81 by matching factors method

Factors of 78

List of positive integer factors of 78 that divides 78 without a remainder.

1,2,3,6,13,26,39,78

Factors of 81

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

1,3,9,27,81

Greatest Common Factor

We found the factors and prime factorization of 78 and 81. The biggest common factor number is the GCF number.
So the greatest common factor 78 and 81 is 3.

Also check out the Least Common Multiple of 78 and 81

Properties of GCF 78 and 81

(i) The GCF of 78 and 81 is associative

GCF of 78 and 81 = GCF of 81 and 78

Related Greatest Common Factor of 78

Related Greatest Common Factor of 81

Frequently Asked Questions on GCF of 78 and 81

1. What is the GCF of 78 and 81?

Answer: GCF of 78 and 81 is 3.

2. What are the Factors of 78?

Answer: Factors of 78 are 1, 2, 3, 6, 13, 26, 39, 78. There are 8 integers that are factors of 78. The greatest factor of 78 is 78.

3. 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.

4. How to Find the GCF of 78 and 81?

Answer:

Greatest Common Factor of 78 and 81 = 3

Step 1: Find the prime factorization of 78

78 = 2 x 3 x 13

Step 2: Find the prime factorization of 81

81 = 3 x 3 x 3 x 3

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 78 and 81 is 3