Fatto generale: 5 is the number of interlocked rings in the symbol of the Olympic Games, representing the number of inhabited continents represented by the Olympians (counting North America and South America as one continent).
Fatto matematico: 5 is the third prime number.
Trivia: 5 is the number of Korotkoff sounds when measuring blood pressure.
Data storica: January 5th is the day in 1918 that the Free Committee for a German Workers Peace, which would become the Nazi Party, is founded.