What is the Least Common Multiple of 1285 and 1290?

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 1285 and 1290 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 1285 and 1290, than apply into the LCM equation.

GCF(1285,1290) = 5
LCM(1285,1290) = ( 1285 × 1290) / 5
LCM(1285,1290) = 1657650 / 5
LCM(1285,1290) = 331530

Least Common Multiple (LCM) of 1285 and 1290 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 1285 and 1290. First we will calculate the prime factors of 1285 and 1290.

Prime Factorization of 1285

Prime Factorization of 1290

Now multiplying the highest exponent prime factors to calculate the LCM of 1285 and 1290.

LCM(1285,1290) = 5¹ × 257¹ × 2¹ × 3¹ × 43¹
LCM(1285,1290) = 331530