The answer to life universe and everything else. Ever since I read Douglas Adams HHGTG, the number 42 has become such an interesting & funny reference to bring up in all contexts. Here is an interesting article from Sciam on various ways number 42 has captured the interest of sci-fi fans.
Few tidbits from the article
“…The author’s choice of the number 42 has become a fixture of geek culture. It’s at the origin of a multitude of jokes and winks exchanged between initiates. If, for example, you ask your search engine variations of the question “What is the answer to everything?” it will most likely answer “42.” Try it in French or German. You’ll often get the same answer whether you use Google, Qwant, Wolfram Alpha (which specializes in calculating mathematical problems) or the chat bot Web app Cleverbot”
“..The number is the sum of the first three odd powers of two—that is, 21 + 23 + 25 = 42.”
“The number 42 is the sum of the first two nonzero integer powers of six—that is, 61 + 62 = 42.”
A lot more references to 42 here: [The link]