Umberto Eco "only" had 30,000, and even he hadn't read most of them in his life (hence why it's called the "anti-library" [0]. Or the Japanese word "tsundoku" [1]).

If nothing else, the energy efficiency of this house must be very good.

[0] https://news.ycombinator.com/item?id=14087536 ("Umberto Eco's Anti-Library")

[1] https://news.ycombinator.com/item?id=25429940 ("Tsundoku: The art of buying books and never reading them")