Jenny's constant is the irrationl number that approximates the rational number 867.5309, famous from the Tommy Tutone song "867-5309/Jenny" (see A104175). Its decimal expansion is 867.53090198168540975582752249614318384... (see A182369). This number is believed to first have appeared identified as such in a Munroe xkcd cartoon. A few people have noticed that "1981" (the year the song was released) appears in the decimal expansion of this number after the second zero from the decimal point.
The protagonist of the song saw Jenny's "name and [telephone] number on the wall," and urges her not to change her number, which he then recites a number of times as if to not forget it. The song was composed by Alex Call and Jim Keller, and has a duration just shy of 4 minutes.
- xkcd, A Table of Slightly Wrong Equations and Identities Useful for Approximations and/or Trolling Teachers April 26, 2012, accessed April 27, 2012. The number is given as
- AllMusic, 867-5309/Jenny, Tommy Tutone