Fatto generale: 18 is the number of bronze monks the Shaolin temple had in Chinese folklore.
Fatto matematico: 18 is a heptagonal number, and as the sum of the first three pentagonal numbers, it is a pentagonal pyramidal number.
Trivia: 18 is the number of chapters into which James Joyce's epic novel Ulysses is divided.
Data storica: January 18th is the day in 1916 that a 611 gram chondrite type meteorite strikes a house near the village of Baxter in Stone County, Missouri.