What is the Least Common Multiple of 21440 and 21455?

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 21440 and 21455 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21440 and 21455, than apply into the LCM equation.

GCF(21440,21455) = 5
LCM(21440,21455) = ( 21440 × 21455) / 5
LCM(21440,21455) = 459995200 / 5
LCM(21440,21455) = 91999040

Least Common Multiple (LCM) of 21440 and 21455 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21440 and 21455. First we will calculate the prime factors of 21440 and 21455.

Prime Factorization of 21440

Prime Factorization of 21455

Now multiplying the highest exponent prime factors to calculate the LCM of 21440 and 21455.

LCM(21440,21455) = 2⁶ × 5¹ × 67¹ × 7¹ × 613¹
LCM(21440,21455) = 91999040