Hecho general: 52003 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 52003 is a boring number.
Trivia: 52003 is an uninteresting number.
Fecha histórica: May 18th is the day in 1896 that the United States Supreme Court rules in Plessy v. Ferguson that the "separate but equal" doctrine is constitutional.