Fait général: 1525 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 1525 is a value of n for which s(f(n)) = 2s(n).
Culture générale: 1525 is an uninteresting number.
Date historique: March 4th is the day in 1814 that Americans defeat the British at the Battle of Longwoods between London, Ontario and Thamesville, near present-day Wardsville, Ontario.