204
200 countries have at least a single athlete
204
205
Well yes there are around 60 countries not competing.
Countries do not enter the Olympic Games. The Olympic Movement consists of international sports federations (IFs), National Olympic Committees (NOCs), and organizing committees for each specific Olympic Games.
104 athletes are competing in the Olympics games for Brazil 2012
240
204 countries or Participating National Olympic Committees took part in the games
Nauru
16
Yes, Russia are competing in the 2012 Summer Olympics in London.
over 500
Shot put