General fact: 2640 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 2640 is an unremarkable number.
Trivia: 2640 is an uninteresting number.
Historical date: March 24th is the day in 2003 that the Arab League votes 21-1 in favor of a resolution demanding the immediate and unconditional removal of U.S. and British soldiers from Iraq.