Fatto generale: 36631 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 36631 is an uninteresting number.
Trivia: 36631 is a boring number.
Data storica: April 16th is the day in 1922 that the Treaty of Rapallo, pursuant to which Germany and the Soviet Union re-establish diplomatic relations, is signed.