42 (forty-two) is the natural number immediately following 41 and directly preceding 43. The number has received considerable attention in popular culture as a result of its central appearance in The Hitchhiker's Guide to the Galaxy as the "Answer to The Ultimate Question of Life, the Universe, and Everything".
The number 42 is, in The Hitchhiker's Guide to the Galaxy by Douglas Adams, "The Answer to the Ultimate Question of Life, the Universe, and Everything", calculated by an enormous supercomputer over a period of 7.5 million years. Unfortunately no one knows what the question is. Thus, to calculate the Ultimate Question, a special computer the size of a small planet was built from organic components and named "Earth". This appeared first in the radio play and later in the novelization of The Hitchhiker's Guide to the Galaxy. The fact that Adams named the episodes of the radio play "fits", the same archaic title for a chapter or section used by Lewis Carroll in "The Hunting of the Snark", suggests that Adams was influenced by Carroll's fascination with and frequent use of the number. The fourth book in the series, the novel So Long, and Thanks for All the Fish, contains 42 chapters. According to the novel Mostly Harmless, 42 is the street address of Stavromula Beta. In 1994 Adams created the 42 Puzzle, a game based on the number 42.
The book 42: Douglas Adams' Amazingly Accurate Answer to Life, the Universe and Everything[15] examines Adams' choice of the number 42 and also contains a compendium of some instances of the number in science, popular culture, and humour.
About the number 42
You're really not going to like it...
"The answer to this is very simple. It was a joke. It had to be a number, an ordinary, smallish number, and I chose that one. Binary representations, base thirteen, Tibetan monks are all complete nonsense. I sat at my desk, stared into the garden and thought '42 will do'. I typed it out. End of story ."
- Douglas Adams.