Hecho matemático: 1617 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 9 stamps.
Trivia: 1617 is a boring number.
Fecha histórica: June 4th is the day in 1928 that President of the Republic of China Zhang Zuolin is assassinated by Japanese agents.