Fatto generale: 5858 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5858 is an uninteresting number.
Trivia: 5858 is an uninteresting number.
Data storica: January 14th is the day in 2004 that the national flag of The Republic of Georgia, the so-called "five cross flag", is restored to official use after a hiatus of some 500 years.