Mathematical fact: 2782 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 19 stamps.
Trivia: 2782 is an unremarkable number.
Historical date: August 13th is the day in 1913 that Otto Witte, an acrobat, is purportedly crowned King of Albania.