All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers
The only odd untouchable (Posted on 2016-04-12) Difficulty: 3 of 5
An untouchable number is a positive integer that is not the sum of the proper divisors of any number(see OEIS A005114).

It is thought that 5 is the only odd untouchable number.

Why?

No Solution Yet Submitted by Ady TZIDON    
No Rating

Comments: ( You must be logged in to post comments.)
  Subject Author Date
SolutionGoldbach SolutionBrian Smith2016-04-12 12:37:55
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information