What is the Least Common Multiple of 720 and 728?

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 720 and 728 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 720 and 728, than apply into the LCM equation.

GCF(720,728) = 8
LCM(720,728) = ( 720 × 728) / 8
LCM(720,728) = 524160 / 8
LCM(720,728) = 65520

Least Common Multiple (LCM) of 720 and 728 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 720 and 728. First we will calculate the prime factors of 720 and 728.

Prime Factorization of 720

Prime Factorization of 728

Now multiplying the highest exponent prime factors to calculate the LCM of 720 and 728.

LCM(720,728) = 2⁴ × 3² × 5¹ × 7¹ × 13¹
LCM(720,728) = 65520