In The Prisoner (1967) starring Patrick McGoohan, there is also an episode called Many Happy Returns (1967). In it, Number 6 is allowed to believe that he has escaped and returned to London. After being returned, he discovers that he was allowed to leave because it was his birthday. In Person of Interest, Jim Caviezel's character is also granted a reprieve on his birthday. Before POI, Jim Caviezel also played the character "Number 6" in the remake of The Prisoner (2009) as well.
Dagmara Dominczyk (Sarah Jennings) also plays Mercedes Iguanada in The Count of Monte Cristo (2002). Jim Caviezel plays the title role.
The board game Reese and Mr. Han are playing is called Xiangqi, a Chinese version of chess.
John Reese's SSN is 380-00-0050, which would have been issued in Michigan.