What is the Least Common Multiple of 390 and 405?

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 390 and 405 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 390 and 405, than apply into the LCM equation.

GCF(390,405) = 15
LCM(390,405) = ( 390 × 405) / 15
LCM(390,405) = 157950 / 15
LCM(390,405) = 10530

Least Common Multiple (LCM) of 390 and 405 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 390 and 405. First we will calculate the prime factors of 390 and 405.

Prime Factorization of 390

Prime Factorization of 405

Now multiplying the highest exponent prime factors to calculate the LCM of 390 and 405.

LCM(390,405) = 2¹ × 3⁴ × 5¹ × 13¹
LCM(390,405) = 10530