# What is the Greatest Common Factor of 18 and 38?

Greatest common factor (GCF) of 18 and 38 is **2**.

GCF(18,38) = 2

We will now calculate the prime factors of **18 and 38**, than find the greatest common factor *(greatest common divisor (gcd))* of the numbers by matching the biggest common factor of 18 and 38.

## How to find the GCF of 18 and 38?

We will first find the prime factorization of 18 and 38. After we will calculate the factors of 18 and 38 and find the biggest common factor number .

### Step-1: Prime Factorization of 18

Prime factors of 18 are 2, 3. Prime factorization of **18** in exponential form is:

18 = 2^{1} × 3^{2}

### Step-2: Prime Factorization of 38

Prime factors of 38 are 2, 19. Prime factorization of **38** in exponential form is:

38 = 2^{1} × 19^{1}

### Step-3: Factors of 18

List of positive integer factors of 18 that divides 18 without a remainder.

1, 2, 3, 6, 9

### Step-4: Factors of 38

List of positive integer factors of 38 that divides 18 without a remainder.

1, 2, 19

#### Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 18 and 38. The biggest common factor number is the **GCF** number.

So the **greatest common factor 18 and 38** is **2**.

Also check out the Least Common Multiple of 18 and 38