What is the Least Common Multiple of 392 and 408?

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 392 and 408 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 392 and 408, than apply into the LCM equation.

GCF(392,408) = 8
LCM(392,408) = ( 392 × 408) / 8
LCM(392,408) = 159936 / 8
LCM(392,408) = 19992

Least Common Multiple (LCM) of 392 and 408 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 392 and 408. First we will calculate the prime factors of 392 and 408.

Prime Factorization of 392

Prime Factorization of 408

Now multiplying the highest exponent prime factors to calculate the LCM of 392 and 408.

LCM(392,408) = 2³ × 7² × 3¹ × 17¹
LCM(392,408) = 19992