Hexakosioihexekontahexaphobia ( n. )

1. The fear of the number six-hundred and sixty-six

Via Wikipedia (breadcrumbs: Route 66 -> Route 666 -> 666 -> Hexakosioihexekontahexaphobia).

As Krissy pointed out, hexakosioihexekontahexaphobia is tied with floccinaucinihilipilification as the longest non-technical word in the English language. But, in a non-monospaced font, hexakosioihexekontahexaphobia will appear much longer, making it cooler. Both words are longer than the oft-mis-cited antidisestablishmentarianism.

• hexakosioihexekontahexaphobia (30 characters)
• floccinaucinihilipilification (30 characters)
• antidisestablishmentarianism (29 characters)

The things I do when I should be working…