Divisibility
Divisibility is the ability of a number to be evenly divided by another number. For example, four divided by two is equal to two, an integer, and therefore we say four is divisible by two.
Divisibility Video
https://youtu.be/6xNkyDgIhEE?t=1699
Notation
We commonly write 
. This means that 
is a divisor of 
. So for the example above, we would write 2|4.
