There is nothing irrational about fearing "the number of the beast", and by extension Satanical manifestations. I have just consulted several dictionaries for hexakosioihexekontahexaphobia
and the word "irrational" is not in any of them. Clearly this is a gratuitous opinion, which in no way affects the solution to this puzzle.
As the song says: "I'm not crazy, I'm just a little unwell. I know right now it's hard to tell."
p.s. -- Just kidding. No retort necessary. Honk if you agree.