# What is the HCF of 18,54 and 81?

HCF of two numbers 18, 54, and 81 is the largest possible number which divides the given numbers exactly.

## Answer: HCF of 18, 54, and 81 is 9

Let us see how to find the HCF of 16 and 24

## Explanation:

The highest common factor of two numbers is the largest possible number which divides both the numbers exactly without any remainder.

We can find the HCF of the numbers in many ways, the commonly used methods are listed below.

## Methods to Find HCF of 18, 54, and 81

- Prime factorization Method
- Listing the common factors method
- Long division Method

### Method1 : HCF of 18, 54, and 81 by Prime Factorization

In this method, we represent 18, 54, and 81 as a product of its prime numbers

Prime factorization of 18 is 2 × 3 x 3

Prime factorization of 54 is 2 × 3 x 3 x 3

Prime factorization of 81 is 3 × 3 x 3 x 3

Common factor = 3, 3

HCF is the product of the factors that are common to each of the given numbers.

HCF is 3 x 3 = 9

### Method2: HCF of 18, 54, and 81 by Long Division

- Step 1: Divide 81 by 18 and check the remainder.
- Step 2: Make the remainder of the above step as the divisor and the divisor of the above step as the dividend and perform the long division again.
- Step 3: Continue till you get the remainder as 0

- Step 4: Take that last divisor as the common factor of 18 and 81
- Step 5: Divide 54 with the common factor thus obtained.

- Step 6: Divide 54 by 9 and check the remainder.
- Step 7: Continue till you get remainder as 0

Irrespective of the method, the solution to our question HCF of 18, 54, and 81 is the same.