Fait général: 1668 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 1668 is the maximum number of regions space can be divided into by 18 spheres.
Culture générale: 1668 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: July 25th is the day in 315 that the Arch of Constantine is completed near the Colosseum at Rome to commemorate Constantine's victory over Maxentius at the Milvian Bridge.