What is the Least Common Multiple of 42 and 204?

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 of 42 and 204 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 42 and 204, than apply into the LCM equation.

GCF(42,204) = 6
LCM(42,204) = ( 42 × 204) / 6
LCM(42,204) = 8568 / 6
LCM(42,204) = 1428

Least Common Multiple (LCM) of 42 and 204 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 42 and 204. First we will calculate the prime factors of 42 and 204.

Prime Factorization of 42

Prime Factorization of 204

Now multiplying the highest exponent prime factors to calculate the LCM of 42 and 204.

LCM(42,204) = 2² × 3¹ × 7¹ × 17¹
LCM(42,204) = 1428