Brute force primality testing of every single integer in existence? Easy. Pi to the last digit? Piece of cake. Halting Problem? Sa-holved.
This is obviously tongue in cheek, and only serves to establish that the computer is "larger than life" and that therefore we should automatically accept all the subsequent descriptions of how the computer can instantly simulate the entire universe and then some.
The reader is not supposed to believe quantum computers actually work like that. The computer is just a storytelling device, no more, no less.