Of the numbers below, 5 of them add up to 2006, and only those five. The question is... which ones? No need to cheat by writing a program to try all possible combinations, there is an easier way

Originally posted by Knight Square The only way i can think of is trial and error, but that will take forever.

I'm thinking going by the last numbers might work. Get two pairs which each add to a number with a 0 at the end then add one that has a 6 at the end. Otherwise it would be trial and error.

I decided I am too lazy to actually try it though.

Originally posted by Mixo What are Harshad numbers? I suppose I could search on Google but an answer here might interest many who are following this thread.

Those divisible by the sum of their digits, and a source of great joy to many.

Google loads rather quickly through modern connections.

Originally posted by aginis 351, 378, 386, 428, 463
no i didn't use trial and error

And we have a winner!

For those still trying to figure it out, Bowmann's observation that most of them are composites is on the right track. Keep looking in this direction for something more specific.