I found a new rule in divisibility rule of 11. The rule states that if a middle number is the sum of two rest digit of a given number then the number is divisible by 11. But I think this rule is applicable only on 3 digit numbers. For example: (495) .9 is the sum of two numbers 4 and 5 which serves our first and last number respectively. Therefore 495 is divisible by 11.