Fatto generale: 21 is the number of demands which were sent to the Chinese government by the Japanese government of Okuma Shigenobu in 1915.
Fatto matematico: 21 is the smallest number of differently sized squares needed to square the square.
Trivia: 21 is the number of demands which were sent to the Chinese government by the Japanese government of Okuma Shigenobu in 1915.
Data storica: January 21st is the day in 1977 that President Jimmy Carter pardons nearly all American Vietnam War draft evaders, some of whom had emigrated to Canada.