Greatest Common Factor of 90 and 91

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 90, 91 i.e. 1 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 90 and 91 is 1.

GCF(90,91) = 1

GCF of 90 and 91

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

GCF of:
and

Greatest Common Factor of 90 and 91

GCF of 90 and 91 is 1

Prime Factorization of 90


2 90
3 45
3 15
5 5
1

Prime factors of 90 are 2,3,5. Prime factorization of 90 in exponential form is:

90 = 21×32×51

Prime Factorization of 91


7 91
13 13
1

Prime factors of 91 are 7,13. Prime factorization of 91 in exponential form is:

91 = 71×131

∴ So by taking common prime factors GCF of 90 and 91 is 1

Greatest Common Factor of 90 and 91 by matching factors method

Factors of 90

List of positive integer factors of 90 that divides 90 without a remainder.

1,2,3,5,6,9,10,15,18,30,45,90

Factors of 91

List of positive integer factors of 91 that divides 91 without a remainder.

1,7,13,91

Greatest Common Factor

We found the factors and prime factorization of 90 and 91. The biggest common factor number is the GCF number.
So the greatest common factor 90 and 91 is 1.

Also check out the Least Common Multiple of 90 and 91

Properties of GCF 90 and 91

(i) The GCF of 90 and 91 is associative

GCF of 90 and 91 = GCF of 91 and 90

Frequently Asked Questions on GCF of 90 and 91

1. What is the GCF of 90 and 91?

Answer: GCF of 90 and 91 is 1.

2. What are the Factors of 90?

Answer: Factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90. There are 12 integers that are factors of 90. The greatest factor of 90 is 90.

3. What are the Factors of 91?

Answer: Factors of 91 are 1, 7, 13, 91. There are 4 integers that are factors of 91. The greatest factor of 91 is 91.

4. How to Find the GCF of 90 and 91?

Answer:

Greatest Common Factor of 90 and 91 = 1

Step 1: Find the prime factorization of 90

90 = 2 x 3 x 3 x 5

Step 2: Find the prime factorization of 91

91 = 7 x 13

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

GCF = = 1

Step 4: Therefore, the greatest common factor of 90 and 91 is 1