What is the Least Common Multiple of 21665 and 21680?

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 21665 and 21680 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21665 and 21680, than apply into the LCM equation.

GCF(21665,21680) = 5
LCM(21665,21680) = ( 21665 × 21680) / 5
LCM(21665,21680) = 469697200 / 5
LCM(21665,21680) = 93939440

Least Common Multiple (LCM) of 21665 and 21680 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21665 and 21680. First we will calculate the prime factors of 21665 and 21680.

Prime Factorization of 21665

Prime Factorization of 21680

Now multiplying the highest exponent prime factors to calculate the LCM of 21665 and 21680.

LCM(21665,21680) = 5¹ × 7¹ × 619¹ × 2⁴ × 271¹
LCM(21665,21680) = 93939440