Fait général: 1421 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 1421 is a value of n for which s(f(n)) = 2s(n).
Culture générale: 1421 is a boring number.
Date historique: November 21st is the day in 1990 that the Charter of Paris for a New Europe refocuses the efforts of the Conference for Security and Co-operation in Europeon post-Cold War issues.