general_fact: 21 is the number of demands which were sent to the Chinese government by the Japanese government of Okuma Shigenobu in 1915.
math_fact: 21 is the smallest number of distinct squares needed to tile a square.
trivia: 21 is the number of points required to win a game in badminton and table tennis (before 2001).
historical_date: January 21st is the day in 2003 that a 7.6 magnitude earthquake strikes the Mexican state of Colima, killing 29 and leaving approximately 10,000 people homeless.