Fait mathématique: 7880 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 26 stamps.
Culture générale: 7880 is an unremarkable number.
Date historique: July 28th is the day in 1948 that the Metropolitan Police Flying Squad foils a bullion robbery in the "Battle of London Airport".