GCD of 57, 81, 28, 21 Calculator

Given Input numbers are 57, 81, 28, 21

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

Divisors of 57

List of positive integer divisors of 57 that divides 57 without a remainder.

1, 3, 19, 57

Divisors of 81

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

1, 3, 9, 27, 81

Divisors of 28

List of positive integer divisors of 28 that divides 28 without a remainder.

1, 2, 4, 7, 14, 28

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 57, 81, 28, 21 . The biggest common divisior number is the GCD number.
So the Greatest Common Divisior 57, 81, 28, 21 is 1.

Therefore, GCD of numbers 57, 81, 28, 21 is 1

Given Input Data is 57, 81, 28, 21

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

Prime Factorization of 57 is 3 x 19

Prime Factorization of 81 is 3 x 3 x 3 x 3

Prime Factorization of 28 is 2 x 2 x 7

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(57, 81) = 1539

GCD(57, 81) = ( 57 x 81 ) / 1539

GCD(57, 81) = 4617 / 1539

GCD(57, 81) = 3

Step2:

Here we consider the GCD from the above i.e. 3 as first number and the next as 28

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

LCM(3, 28) = 84

GCD(3, 28) = ( 3 x 28 ) / 84

GCD(3, 28) = 84 / 84

GCD(3, 28) = 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 57, 81, 28, 21 is 1

Here are some samples of GCD of Numbers calculations.

• GCD of 62, 97, 43, 72
• GCD of 36, 93, 16, 29
• GCD of 63, 34, 37, 73
• GCD of 12, 68, 93, 59
• GCD of 44, 20, 90, 15

1. What is the GCD of 57, 81, 28, 21?

GCD of 57, 81, 28, 21 is 1

2. Where do I get the detailed procedure to find GCD of 57, 81, 28, 21?

You can find a detailed procedure to find GCD of 57, 81, 28, 21 on our page.

3. How to find GCD of 57, 81, 28, 21 on a calculator?

You can find the GCD of 57, 81, 28, 21 by simply giving the inputs separated by commas and click on the calculate button to avail the Greatest Common Divisor in less time.