A Number is divisible by:  


Its unit's digit is 0,2,4,6 or 8.  36 is divisible but not 39. 
The sum of its digit is divisible by 3.  144 (1+ 4 + 4 = 9 ÷3 = 3) yes  
The number formed by its digit in ten's and unit's place is divisble by 4.  348 (48 ÷ 4 =12) yes  
Its unit's digit is 0 or 5.  450 , 855 is divisible but not 806.  

It is divisible by both 2 and 3.  114 (it is even, and 1+1+4=6 and 6÷3 = 2) Yes 308 (it is even, but 3+0+8=11 and 11÷3 = which is not a whole number) No 
If you double the last digit and subtract it from the rest of the number and the answer is: 1) 0, or 2) divisible by 7 (Note: you can apply this rule to that answer again if you want)  672 (Double 2 is 4, 674=63, and 63÷7=9) Yes 905 (Double 5 is 10, 9010=80, and 80÷7=not a whole number) No 

A number is divisible by 8.if the number formed by its digits in hundred's,ten's and units places are divisible by 8  109816 (816÷8=102) Yes 216302 (302÷8 = not a whole number) No 

A number is divisible by 9,if the sum of its digits is divisible by 9  1629 (1+6+2+9=18, and again, 1+8=9) Yes 2013 (2+0+1+3=6) No 


A number is divisible by 10 if its unit's place digits is zero  240 is 221 is not 
A number is divisible by 11,if the difference of the sum of its digits in odd places and the sum of its digits in even places is eiether 0 or multiple of 11  1364 ((3+4)  (1+6) = 0) Yes
3729 ((7+9)  (3+2) = 11) Yes 25176 ((5+7)  (2+1+6) = 3) No 


A number is divisible by 12 if it is divisible by 4 & 3  648 (6+4+8=18 and 18÷3=6, also 48÷4=12) Yes 916 (9+1+6=16, 16÷3= 5 1/3) No 

A number is divisible by 15 if it is divisible by 3 and 5 both  465 is divisible by 3 and 5 both so with 15 yes otherwise No. 

A number is divisible by 16 if the number formed by the last 4 digits is divisible by 16  25,8000 ( 8000÷ 16 = 500) yes 
A number is divisible by if it is divisible by 2 & 9 both  450( 4+5+0= 9 ÷ 9) yes 450 ÷ 2 =225 yes 450 is divisible by 18 


A number is divisible by 20 if its units digit is 0 and its tens digit is even  780 ( unit digit 0 and tens digit is 8 even number) yes 
A number is divisible by 22 if it is divisible by 2 & 11  4466 ( (4+6) (4+6))= 0 yes by 11 and 4466 ÷ 2 =406 so yes by 22 


A number is divisible by 25 if the number formed by the last two digits is any of 0,25,50 or 75  1225 ( last two digits are 25) yes 