147573952589676412927 is a robot recipient of a package delivered by Bender to the planet Chapek 9, the robot separatist home world in "Free Will Hunting." As humans are hunted as a Xeno-phobic passtime on Chapek 9, only Bender can make the delivery while Fry and Leela stay on board the Planet Express Ship in orbit. When making the delivery, Bender is sprayed in the face with nerve gas through the peephole of 147573952589676412927's door as a measure to prove he isn't a human.
147573952589676412927 may or may not be the robot who discovered Fry urinating behind a trash bin and offered to seal his coolant leak with hot resin when Leela, Fry and Bender made their first visit to Chapek 9. His appearance and voice were the same as that unit, but a robot's appearance and voice are not necessarily unique.
Also, 2^67 - 1 = 147573952589676412927.
See also Frank Nelson Cole.