What is the Least Common Multiple of 81705 and 81720?

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 81705 and 81720 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 81705 and 81720, than apply into the LCM equation.

GCF(81705,81720) = 15
LCM(81705,81720) = ( 81705 × 81720) / 15
LCM(81705,81720) = 6676932600 / 15
LCM(81705,81720) = 445128840

Least Common Multiple (LCM) of 81705 and 81720 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 81705 and 81720. First we will calculate the prime factors of 81705 and 81720.

Prime Factorization of 81705

Prime Factorization of 81720

Now multiplying the highest exponent prime factors to calculate the LCM of 81705 and 81720.

LCM(81705,81720) = 3² × 5¹ × 13¹ × 419¹ × 2³ × 227¹
LCM(81705,81720) = 445128840