GCD of 91, 56, 80, 21 Calculator

Given Input numbers are 91, 56, 80, 21

To find the GCD of numbers using factoring list out all the divisors of each number

Divisors of 91

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

1, 7, 13, 91

Divisors of 56

List of positive integer divisors of 56 that divides 56 without a remainder.

1, 2, 4, 7, 8, 14, 28, 56

Divisors of 80

List of positive integer divisors of 80 that divides 80 without a remainder.

1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Divisors of 21

List of positive integer divisors of 21 that divides 21 without a remainder.

1, 3, 7, 21

Greatest Common Divisior

We found the divisors of 91, 56, 80, 21 . The biggest common divisior number is the GCD number.
So the Greatest Common Divisior 91, 56, 80, 21 is 1.

Therefore, GCD of numbers 91, 56, 80, 21 is 1

Given Input Data is 91, 56, 80, 21

Make a list of Prime Factors of all the given numbers initially

Prime Factorization of 91 is 7 x 13

Prime Factorization of 56 is 2 x 2 x 2 x 7

Prime Factorization of 80 is 2 x 2 x 2 x 2 x 5

Prime Factorization of 21 is 3 x 7

The above numbers do not have any common prime factor. So GCD is 1

Step1:

Let's calculate the GCD of first two numbers

The formula of GCD is GCD(a, b) = ( a x b) / LCM(a, b)

LCM(91, 56) = 728

GCD(91, 56) = ( 91 x 56 ) / 728

GCD(91, 56) = 5096 / 728

GCD(91, 56) = 7

Step2:

Here we consider the GCD from the above i.e. 7 as first number and the next as 80

The formula of GCD is GCD(a, b) = ( a x b) / LCM(a, b)

LCM(7, 80) = 560

GCD(7, 80) = ( 7 x 80 ) / 560

GCD(7, 80) = 560 / 560

GCD(7, 80) = 1

Step3:

Here we consider the GCD from the above i.e. 1 as first number and the next as 21

The formula of GCD is GCD(a, b) = ( a x b) / LCM(a, b)

LCM(1, 21) = 21

GCD(1, 21) = ( 1 x 21 ) / 21

GCD(1, 21) = 21 / 21

GCD(1, 21) = 1

GCD of 91, 56, 80, 21 is 1

Here are some samples of GCD of Numbers calculations.

• GCD of 76, 72, 76, 12
• GCD of 96, 71, 93, 60
• GCD of 34, 83, 57, 33
• GCD of 78, 46, 69, 53
• GCD of 13, 15, 93, 47

1. What is the GCD of 91, 56, 80, 21?

GCD of 91, 56, 80, 21 is 1

2. Where do I get the detailed procedure to find GCD of 91, 56, 80, 21?

You can find a detailed procedure to find GCD of 91, 56, 80, 21 on our page.

3. How to find GCD of 91, 56, 80, 21 on a calculator?

You can find the GCD of 91, 56, 80, 21 by simply giving the inputs separated by commas and click on the calculate button to avail the Greatest Common Divisor in less time.