What is the Least Common Multiple of 620 and 639?

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 620 and 639 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 620 and 639, than apply into the LCM equation.

GCF(620,639) = 1
LCM(620,639) = ( 620 × 639) / 1
LCM(620,639) = 396180 / 1
LCM(620,639) = 396180

Least Common Multiple (LCM) of 620 and 639 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 620 and 639. First we will calculate the prime factors of 620 and 639.

Prime Factorization of 620

Prime Factorization of 639

Now multiplying the highest exponent prime factors to calculate the LCM of 620 and 639.

LCM(620,639) = 2² × 5¹ × 31¹ × 3² × 71¹
LCM(620,639) = 396180