/ran-dəm nəm-bərz/
n.
When one wishes to specify a large but random number of things, and the context is inappropriate for N, certain numbers are preferred by hacker tradition (that is, easily recognized as placeholders). These include the following:
17
Long described at MIT as the least random number
See 23.
23
Sacred number of Eris, Goddess of Discord (along with 17 and 5).
42
The Answer to the Ultimate Question of Life, the Universe, and Everything. (Note that this answer is completely fortuitous. ?)
69
From the sexual act. This one was favored in MIT's ITS culture.
105
69 hex = 105 decimal, and
69 decimal = 105 octal.
666
The Number of the Beast.
For further enlightenment, consult the Principia Discordia, The Hitchhiker's Guide to the Galaxy, The Joy of Sex, and the Christian Bible (Revelation 13:8).
See also Discordianism or consult your pineal gland.
One common rhetorical maneuver uses any of the canonical random numbers as placeholders for variables.
"The max function takes 42 arguments, for arbitrary values of 42."
"There are 69 ways to leave your lover, for 69 = 50."
This is especially likely when the speaker has uttered a random number and realizes that it was not recognized as such, but even non-random numbers are occasionally used in this fashion. A related joke is that pi equals 3 -- for small values of pi and large values of 3.