Fatto generale: 47581 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 47581 is an unremarkable number.
Trivia: 47581 is a boring number.
Data storica: April 9th is the day in 1682 that Robert Cavelier de La Salle discovers the mouth of the Mississippi River, claims it for France and names it Louisiana.