Fatto generale: 1601 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1601 is the number of forests with 12 vertices.
Trivia: 1601 is an uninteresting number.
Data storica: May 19th is the day in 2007 that President of Romania Traian Băsescu survives an impeachment referendum and returns to office from suspension.