What is the Least Common Multiple of 19981 and 19989?

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 19981 and 19989 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 19981 and 19989, than apply into the LCM equation.

GCF(19981,19989) = 1
LCM(19981,19989) = ( 19981 × 19989) / 1
LCM(19981,19989) = 399400209 / 1
LCM(19981,19989) = 399400209

Least Common Multiple (LCM) of 19981 and 19989 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 19981 and 19989. First we will calculate the prime factors of 19981 and 19989.

Prime Factorization of 19981

Prime Factorization of 19989

Now multiplying the highest exponent prime factors to calculate the LCM of 19981 and 19989.

LCM(19981,19989) = 13¹ × 29¹ × 53¹ × 3² × 2221¹
LCM(19981,19989) = 399400209