Fait général: 4187 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 4187 is the smallest Rabin-Miller pseudoprime with an odd reciprocal period.
Culture générale: 4187 is an uninteresting number.
Date historique: June 18th is the day in 1264 that the Parliament of Ireland meets at Castledermot in County Kildare, the first definitively known meeting of this Irish legislature.