What is the Least Common Multiple of 840 and 857?

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 840 and 857 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 840 and 857, than apply into the LCM equation.

GCF(840,857) = 1
LCM(840,857) = ( 840 × 857) / 1
LCM(840,857) = 719880 / 1
LCM(840,857) = 719880

Least Common Multiple (LCM) of 840 and 857 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 840 and 857. First we will calculate the prime factors of 840 and 857.

Prime Factorization of 840

Prime Factorization of 857

Now multiplying the highest exponent prime factors to calculate the LCM of 840 and 857.

LCM(840,857) = 2³ × 3¹ × 5¹ × 7¹ × 857¹
LCM(840,857) = 719880