# Greatest Common Factor of 18 and 40

Greatest common factor (GCF) of 18 and 40 is **2**.

GCF(18,40) = 2

We will now calculate the prime factors of **18 and 40**, than find the greatest common factor *(greatest common divisor (gcd))* of the numbers by matching the biggest common factor of 18 and 40.

## Prime Factorization of 18

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

18 = 2^{1} × 3^{2}

## Prime Factorization of 40

Prime factors of 40 are 2, 5. Prime factorization of **40** in exponential form is:

40 = 2^{3} × 5^{1}

### Factors of 18

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

1, 2, 3, 6, 9

### Factors of 40

List of positive integer factors of 40 that divides 18 without a remainder.

1, 2, 4, 5, 8, 10, 20

### Greatest Common Factor

We found the factors and prime factorization of 18 and 40. The biggest common factor number is the **GCF** number.

So the **greatest common factor 18 and 40** is **2**.

Also check out the Least Common Multiple of 18 and 40

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