What is the Least Common Multiple of 1680 and 1691?

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 1680 and 1691 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 1680 and 1691, than apply into the LCM equation.

GCF(1680,1691) = 1
LCM(1680,1691) = ( 1680 × 1691) / 1
LCM(1680,1691) = 2840880 / 1
LCM(1680,1691) = 2840880

Least Common Multiple (LCM) of 1680 and 1691 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 1680 and 1691. First we will calculate the prime factors of 1680 and 1691.

Prime Factorization of 1680

Prime Factorization of 1691

Now multiplying the highest exponent prime factors to calculate the LCM of 1680 and 1691.

LCM(1680,1691) = 2⁴ × 3¹ × 5¹ × 7¹ × 19¹ × 89¹
LCM(1680,1691) = 2840880