Fatto generale: 4687 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4687 is a value of n for which s(f(n)) = 3s(n).
Trivia: 4687 is a boring number.
Data storica: October 30th is the day in 1944 that Anne Frank and sister Margot Frank are deported from Auschwitz to the Bergen-Belsen concentration camp.