Question 49341
"Divisibility" is the ability to divide one number by another number with no remainder. Here are some examples: (Note: the slash (/) means "divided by")

9 is divisble by 3 because {{{9/3 = 3}}} with no remainder.

51 is divisble by 17 because {{{51/17 = 3}}} with no remainder.

But:

13 is not divisble by 4 because {{{13/4}}} = 3 and remainder of 1.

It would be very useful for you to become familiar the "Divisibility rules"

A number is divisble by...

2 if it is an even number.
3 if the sum of the digits is divisible by 3.
4 if the last two digits (tens and ones digits) are divible by 4.
5 if the one's digit is 5 or 0.
6 if the number is divisble by both 2 and 3.
7 No rule for 7.
8 No rule for 8 but try 2 then 4.
9 if the sum of the digits is divisble by 9.
10 if the ones digit is 0.