Fatto generale: 5118 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5118 is the maximum value of n so that there exist 6 denominations of stamps so that every postage from 1 to n can be paid for with at most 12 stamps.
Trivia: 5118 is an uninteresting number.
Data storica: January 4th is the day in 1884 that the Fabian Society is founded in London.