Fatto generale: 25313 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 25313 is a boring number.
Trivia: 25313 is a boring number.
Data storica: April 20th is the day in 1865 that Astronomer Pietro Angelo Secchi demonstrates the Secchi disk, which measures water clarity, aboard Pope Pius IX's yacht, the L’Immaculata Concezion.