Fatto generale: 64 is the total number of black and white squares on the game board in chess or draughts.
Fatto matematico: 64 is the index of Graham's number in the rapidly growing sequence 3,27,7625597484987,....
Trivia: 64 is the number of Braille characters in the old 6-dot system.
Data storica: March 4th is the day in 1933 that the Parliament of Austria is suspended because of a quibble over procedure – Chancellor Engelbert Dollfuss initiates an authoritarian rule by decree.