**Least common multiple (LCM) is the smallest number that is a multiple of two or more numbers. Learn how to find the LCM of two numbers in JavaScript.**

In arithmetic and number theory, the least common multiple, lowest common multiple, or smallest common multiple of two integers a and b, usually denoted by LCM(a, b), is the smallest positive integer that is divisible by both a and b. Since division of integers by zero is undefined, this definition has meaning only if a and b are both different from zero. However, some authors define lcm(a,0) as 0 for all a, which is the result of taking the lcm to be the least upper bound in the lattice of divisibility.

**Example**

What is the LCM of 4 and 6?

Multiples of 4 are:

```
4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, ...
```

and the multiples of 6 are:

```
6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, ...
```

Common multiples of 4 and 6 are simply the numbers that are in both lists:

```
12, 24, 36, 48, 60, 72, ....
```

So, from this list of the first few common multiples of the numbers 4 and 6, their least common multiple is 12.

**Computing the least common multiple**

The following formula reduces the problem of computing the least common multiple to the problem of computing the greatest common divisor (GCD), also known as the greatest common factor:

```
lcm(a, b) = |a * b| / gcd(a, b)
```

A Venn diagram showing the least common multiples of combinations of 2, 3, 4, 5 and 7 (6 is skipped as it is 2 × 3, both of which are already represented).

For example, a card game which requires its cards to be divided equally among up to 5 players requires at least 60 cards, the number at the intersection of the 2, 3, 4 and 5 sets, but not the 7 set.

**References**

Wikipedia

**The ****Original Article**** can be found on https://github.com**

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