# What is the Least Common Multiple of 4 and 19?

*Least common multiple* or lowest common denominator (lcd) can be calculated in two way; with the LCM formula calculation of greatest common factor (GCF), or multiplying the prime factors with the highest exponent factor.

Least common multiple (LCM) of 4 and 19 is **76**.

LCM(4,19) = 76

## Least Common Multiple of 4 and 19 with GCF Formula

The formula of **LCM** is LCM(a,b) = ( a × b) / GCF(a,b).

We need to calculate greatest common factor 4 and 19, than apply into the LCM equation.

GCF(4,19) = 1

LCM(4,19) = ( 4 × 19) / 1

LCM(4,19) = 76 / 1

LCM(4,19) = 76

## Least Common Multiple (LCM) of 4 and 19 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 4 and 19. First we will calculate the **prime factors of 4 and 19**.

### Prime Factorization of 4

Prime factors of 4 are 2. Prime factorization of **4** in exponential form is:

4 = 2^{2}

### Prime Factorization of 19

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

19 = 19^{1}

Now multiplying the highest exponent prime factors to calculate the **LCM of 4 and 19**.

LCM(4,19) = 2^{2} × 19^{1}

LCM(4,19) = 76