What is the Least Common Multiple of 21720 and 21724?

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 21720 and 21724 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21720 and 21724, than apply into the LCM equation.

GCF(21720,21724) = 4
LCM(21720,21724) = ( 21720 × 21724) / 4
LCM(21720,21724) = 471845280 / 4
LCM(21720,21724) = 117961320

Least Common Multiple (LCM) of 21720 and 21724 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21720 and 21724. First we will calculate the prime factors of 21720 and 21724.

Prime Factorization of 21720

Prime Factorization of 21724

Now multiplying the highest exponent prime factors to calculate the LCM of 21720 and 21724.

LCM(21720,21724) = 2³ × 3¹ × 5¹ × 181¹ × 5431¹
LCM(21720,21724) = 117961320