Fatto matematico: 1579 is the smallest prime that remains prime when preceded and followed by one, two, three, or four 9's.
Trivia: 1579 is an uninteresting number.
Data storica: April 27th is the day in 1578 that Duel of the Mignons claims the lives of two favourites of Henry III of France and two favorites of Henry I, Duke of Guise.