Fatto generale: 52 is the number of cards in a standard deck of playing cards, not counting Jokers or advertisement cards.
Fatto matematico: 52 is the 6th Bell number and a decagonal number.
Trivia: 52 is the approximate number of weeks in a year.
Data storica: February 21st is the day in 1804 that the first self-propelling steam locomotive makes its outing at the Pen-y-Darren Ironworks in Wales.