What is the Least Common Multiple of 646 and 665?

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 646 and 665 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 646 and 665, than apply into the LCM equation.

GCF(646,665) = 19
LCM(646,665) = ( 646 × 665) / 19
LCM(646,665) = 429590 / 19
LCM(646,665) = 22610

Least Common Multiple (LCM) of 646 and 665 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 646 and 665. First we will calculate the prime factors of 646 and 665.

Prime Factorization of 646

Prime Factorization of 665

Now multiplying the highest exponent prime factors to calculate the LCM of 646 and 665.

LCM(646,665) = 2¹ × 17¹ × 19¹ × 5¹ × 7¹
LCM(646,665) = 22610