What is 8487 divisibility rule?

Answer 1

The number must be divisible by 9, 23 and 41, so all three of the following conditions must be met.

• Divisibility by 9 requires you to check the sum of the digits is divisible by 9.
  
• Divisibility by 23 requires you to add 7 times the last digit to the rest. The answer must be divisible by 23 directly.
• For divisibility by 41, subtract 4 times the last digit from the rest. The answer must be divisible by 23 directly.
  

In each case, the additions or subtractions can be repeated so as to make the answer easier to test for divisibility.