Mathematical fact: 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 unremarkable number.
Historical date: January 4th is the day in 1974 that United States President Richard Nixon refuses to hand over materials subpoenaed by the Senate Watergate Committee.