Why is Stitch called 626?
The experiment number for Stitch is “626” which is an area code for the San Gabriel Valley in Southern California (Whether one of the writers for the movie lives or is from this area is not known).
Does 625 have a name?
625 is never given a name during the course of the series, though Lilo calls him “Sandwich Boy” in the episode “627”. In one episode, when Gantu and Stitch are having an argument about who should be the leader of their opposing teams, 625 nominates Lilo, and with a majority vote she becomes their leader.