Fatto matematico: 6745 is the maximum value of n so that there exist 4 denominations of stamps so that every postage from 1 to n can be paid for with at most 25 stamps.
Trivia: 6745 is an unremarkable number.
Data storica: June 19th is the day in 1990 that the current international law defending indigenous peoples, Indigenous and Tribal Peoples Convention, 1989, is ratified for the first time by Norway.