In the year 2010, there are 22 teams.
18
Between 18-22 teams with 9 riders in each.
The most well known Tour de France is a bicycle race, not a running race.
TEAM SKY is the team that are in the 2014 Tour de France.
Two. Astana and Saxo Bank
there is no national teams at the tour de france, every team is multinational
You cannot enter the Tour de France; the UCI and ASO invite ProTour/UCI sanctioned teams to compete.
Garmin and Team Columbia highroad
Professional riders arranged in teams.
There are typically around 20 teams, although it varies each year. Each team with 9 riders.
According to the Tour official site, there are 22 teams participating.
Simply because a group of riders can do better than riders competing on their own, which turns most longer races into team events. If you want bicycle races that are run individually, look for time trial events.