Fait mathématique: 4751 is the starting location of 8888 in the decimal expansion of p.
Culture générale: 4751 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 2nd is the day in 1959 that Luna 1, the first spacecraft to reach the vicinity of the Moon and to orbit the Sun, is launched by the Soviet Union.