Fatto generale: 4422 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4422 is the maximum value of n so that there exist 5 denominations of stamps so that every postage from 1 to n can be paid for with at most 15 stamps.
Trivia: 4422 is an uninteresting number.
Data storica: February 8th is the day in 1587 that Mary, Queen of Scots, is executed on suspicion of having been involved in the Babington Plot to murder her cousin, Queen Elizabeth I.