Fatto generale: 6578 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 6578 is the smallest number which can be written as the sum of three 4^{th} powers in 2 ways.
Trivia: 6578 is an unremarkable number.
Data storica: January 3rd is the day in 1996 that the Motorola StarTAC, the first flip phone and one of the first mobile phones to gain widespread consumer adoption, goes on sale.