Fait général: 2644 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 2644 is a boring number.
Culture générale: 2644 is an uninteresting number.
Date historique: March 28th is the day in 2005 that the 2005 Sumatra earthquake rocks Indonesia, and at magnitude 8.7 is the fourth strongest earthquake since 1965.