What is the Least Common Multiple of 21981 and 21987?

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 21981 and 21987 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21981 and 21987, than apply into the LCM equation.

GCF(21981,21987) = 3
LCM(21981,21987) = ( 21981 × 21987) / 3
LCM(21981,21987) = 483296247 / 3
LCM(21981,21987) = 161098749

Least Common Multiple (LCM) of 21981 and 21987 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21981 and 21987. First we will calculate the prime factors of 21981 and 21987.

Prime Factorization of 21981

Prime Factorization of 21987

Now multiplying the highest exponent prime factors to calculate the LCM of 21981 and 21987.

LCM(21981,21987) = 3² × 17¹ × 431¹ × 7¹ × 349¹
LCM(21981,21987) = 161098749