Fatto generale: 13963 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 13963 is a boring number.
Trivia: 13963 is an unremarkable number.
Data storica: 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.