# What is the Least Common Multiple of 57 and 70?

*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 57 and 70 is **3990**.

LCM(57,70) = 3990

## Least Common Multiple of 57 and 70 with GCF Formula

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

We need to calculate greatest common factor 57 and 70, than apply into the LCM equation.

GCF(57,70) = 1

LCM(57,70) = ( 57 × 70) / 1

LCM(57,70) = 3990 / 1

LCM(57,70) = 3990

## Least Common Multiple (LCM) of 57 and 70 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 57 and 70. First we will calculate the **prime factors of 57 and 70**.

### Prime Factorization of 57

Prime factors of 57 are 3, 19. Prime factorization of **57** in exponential form is:

57 = 3^{1} × 19^{1}

### Prime Factorization of 70

Prime factors of 70 are 2, 5, 7. Prime factorization of **70** in exponential form is:

70 = 2^{1} × 5^{1} × 7^{1}

Now multiplying the highest exponent prime factors to calculate the **LCM of 57 and 70**.

LCM(57,70) = 3^{1} × 19^{1} × 2^{1} × 5^{1} × 7^{1}

LCM(57,70) = 3990