What is LCM?
The least common multiple (also called the lowest common multiple or smallest common multiple or LCM) of one or more integer numbers is the smallest positive integer divisible by all these numbers.
One way to find the least common multiple of two numbers is first to list the prime factors of each number. Then multiply each factor the greatest number of times it occurs in either number. If the same factor occurs more than once in both numbers, you multiply the factor by the greatest number of times it occurs.
For three or more numbers, proceed similarly, multiple the largest found powers of prime factors of given numbers.