I've got your number

A couple of weeks back, I talked about the term 86, which is restaurant slang for something like "we're out of." This is probably where Maxwell Smart of Get Smart got his numeric designation. 
If there's a special significance to 24601, Jean Valjean's prisoner number in Les Miserables, it's been lost to history. Some allege that Victor Hugo chose the number because it was the day he himself was conceived, and that seems even more silly after writing it out than it did when I was reading it. 
If you watched Star Trek: The Next Generation, then you know that Captain Picard's nickname for his first mate William Riker is Number One. But you may not know that Riker wasn't the first Star Trek character to be called Number One. In the pilot episode of the original Star Trek series, actress Majel Barrett played the ship's first mate, known only as Number One. Barrett's character was left out of the series - seems that, for studio execs, interstellar travel was less farfetched than the idea of a first mate with a vagina. 

Also more believable than a woman first mate.

Don't feel bad for Barrett, though - she eventually earned a new numeric nickname - First Lady of Star Trek. This isn't just because she married show creator Gene Roddenberry. She also played Nurse Christine Chapel, who was promoted to Doctor Chapel for the films. She played Ambassador Lwaxana Troi (the Federation's first female drag queen) in The Next Generation and Deep Space 9, and was the voice of the computer in the original series, The Next Generation, Deep Space 9, Voyager, and a couple of episodes of Enterprise, making her the only actor to appear in all of the television series. 
If you're not a Dr. Who fan, you should probably become one. Once you do, you'll learn that the titular doctor's name isn't Who, it's just The Doctor. In recent years, Who fans have started referring to the 13 actors who have played the doctor by the order in which they appeared on the series. Tom Baker, who wore the mantel (and the scarf) in the 1970s is known as the 4th Doctor.

David Tenant and Matt Smith are known to many of their fans as just 10 and 11.

The characters in the play 12 Angry Men have no names - they're known only by their juror number. Jack Klugman, Juror #5, was the last angry man standing when he died back in 2012. He outlived most of his costars by decades.