Fatto generale: 483 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 483 is the last 3-digit string in the decimal expansion of p.
Trivia: 483 is a boring number.
Data storica: April 27th is the day in 1967 that Expo 67 officially opens in Montreal, Canada with a large opening ceremony broadcast around the world.