# What is the HCF of 18 and 27?

HCF (Highest Common Factor) of 18 and 27 is the largest possible number which divides the numbers 18 and 27 exactly leaving the remainder as 0

## Answer: HCF of 18 and 27 is 9

We can find the HCF by the following two methods.

## Explanation:

Highest Common Factor of 18 and 27 is the highest number which divides by 18 and 27.

- HCF of 18 and 27 by Long Division
- HCF of 18 and 27 by Prime Factorization

### Method 1: HCF of 18 and 27 by Long Division

**Step 1:** Divide 18 by 27 and check the remainder. Here, the remainder is 9

**Step 2:** Make the remainder 9 as the divisor and the divisor 18 as the dividend and perform the long division again.

**Step 3:** Continue till you get the remainder as 0 and HCF(18, 27) is the last divisor of the division process.

### Method 2: HCF of 18 and 27 by Prime Factorization

We will express the numbers 18 and 27 as a product of their prime factors.

Prime factorization of 18 is 2 × 3 × 3

Prime factorization of 27 is 3 × 3 × 3

The common factors in both prime factorization = 3 × 3

HCF of 18 and 27 is the product of the prime factors that are common to the prime factorization of 18 and 27

So, HCF of 18 and 27 is 9

You can find the HCF in any of the above methods but the solution will be the same.