Find the biggest integer N such that:
1. All its digits are distinct.
2. Each of these digits divides N.

Only a p&p solution requested.

Bonus: What would be the answer, if one of N"s digits were exempted from being its divider?

(In reply to Bonus only--not the actual puzzle. by Charlie)

       Without a computer: as you saw, 0 is out and if you get rid of 5 then 4 must be out and you are  left with 7 digits only.

After a while IF you see that one digit more must leave - 9 of course...?..OR  replace the 4 ,5,  by 1,3,5..???..and leave 9 in..

Now it is not so difficult to carry on  with p&p...

GO AHEAD

Edited on October 13, 2014, 10:22 am

Posted by Ady TZIDON on 2014-10-13 10:07:45