Hecho general: 5050 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 5050 is the sum of the first 100 integers.
Trivia: 5050 is an uninteresting number.
Fecha histórica: October 28th is the day in 1919 that the U.S. Congress passes the Volstead Act over President Woodrow Wilson's veto, paving the way for Prohibition to begin the following January.