Fatto generale: 15855 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 15855 is an uninteresting number.
Trivia: 15855 is an uninteresting number.
Data storica: May 29th is the day in 1167 that Battle of Monte Porzio – A Roman army supporting Pope Alexander III is defeated by Christian of Buch and Rainald of Dassel.