Probably the fact that it is set (mostly) in outer space, though I would consider it comedy first and sci-fi second.
The Hitchhiker's Guide to the Galaxy is published by Del Rey, which is part of Random House. (See related link, below.)
Originally, Pan Books in the UK and Harmony Books in the USA. Today, Del Rey holds the rights in the USA.
the meaning of life, the universe and everything is 42.
Space