Divisible by 2.
A number is divisible by 2  if the last digit is 0, 2, 4, 6 or 8.

Example: 2346 is divisible by 2 since the last digit is 6.

Divisible by 3.
A number is divisible by 3  if the sum of the digits is divisible by 3.

Example: 23457 is divisible by 3 since the sum of the digits is 21 (2 + 3 + 4 + 5+ 7 = 21), and 21 is divisible by 3.

Divisible by 4.
A number is divisible by 4  if the number formed by the last two digits is either 00 or divisible by 4.

Example: 245678952152 is divisible by 4 since 52 is divisible by 4.

Divisible by 5.
A number is divisible by 5  if the last digit is either 0 or 5.

Example: 12457896535 is divisible by 5 since the last digit is 5.

Divisible by 6.
A number is divisible by 6  if it is divisible by and it is divisible by 3.

Example: 256848 is divisible by 6 since it is divisible by 2 and it is divisible by 3.

Divisible by 11.
To check whether a number is divisible by 11, sum the digits in the odd positions counting from the left (the first, third, ....) and then sum the remaining digits. If the difference between the two sums is either 0 or divisible by 11, then so is the original number.

Example: 145879635
Digits in the odd positions: 1+5+7+6+5 = 24
Digits in the even position: 4+8+9+3 = 24
So 145879635 is divisible by 11 since 24-24=0.