Fatto generale: 13557 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 13557 is an uninteresting number.
Trivia: 13557 is an unremarkable number.
Data storica: February 11th is the day in 1990 that Nelson Mandela is released from Victor Verster Prison outside Cape Town, South Africa after 27 years as a political prisoner.