Question

Is it possible to make a number out of 8 different digits that is

Answer 1

Answer:

  1,123,449,768

Step-by-step explanation:

The smallest number composed from 8 different digits that is divisible by each of those digits appears to be the 10-digit number ...

  1,123,449,768

Restrictions

If the number is to be divisible by an even digit, it must be even. That means it cannot end in the digit 5, so 5 cannot be one of the digits. We disallow division by 0, so 0 cannot be one of the digits.

The remaining 8 digits total 40, so cannot form a number divisible by 3, 6, or 9. In order to make such a number, we must add 5 to the digit total, but cannot do so using the single digit 5.

Choices for added digits include {1, 4} and {2, 3}. Adding 9+5 = 14 to the digit total would also work but would guarantee the resulting number is not the minimum possible.

Further divisibility restrictions

The digits we have to work with are now {1, 1, 2, 3, 4, 4, 6, 7, 8. 9}. We know that an even number constructed from these digits will be divisible by 1, 2, 3, 6, and 9. To make it divisible by 4, 7, and 8, it must be a multiple of the LCM of those numbers.

The least possible number will use the smallest digits first, so will start ...

  112344...

The remaining digits, 6, 7, 8, 9, need to form a number that will be divisible by 56 when appended to the 6 digits already used. Those 6 digits form a number, 1123440000, that has a remainder of 32 when divided by 56. Hence we need to use the digits 6, 7, 8, 9 to make a number with a remainder of 24 when divided by 56. There are 24 permutations of the digits 6, 7, 8, 9. Half of these are odd numbers

The one number formed from digits 6, 7, 8, 9 that is divisible by 56 with a remainder of 24 is 9768.

Smallest Number

The smallest number comprised of 8 different digits and divisible by each of them is the 10-digit number 1,123,449,768.