So... im reading fanfiction. And,

[Balmas]

i do believe Fallout:Equestria beats that word count
plus its available in e book...audio book..and recently got published in hardcover
if it doesnt do so by itself you can add in the various side stories(Fallout Equestria: Project Horizons is longer than the original i believe) and absolutely blow that away

from what i hear its pretty damn good...i just dont have the time to start on a story that long atm

I can testify to this. I am a voracious reader, especially of fanfics. Google tells me that Fallout: Equestria itself comes in at 484,000 words. For comparison, an average paperback comes in a 100K. The Lord of the Rings trilogy is 473,000.

I've been reading this story every spare minute for about a week now, and I've only just now reached the half-way point. It is one of, if not the best, grimdark fanfiction. Be warned: it's violent, has profanity, and certain side stories contain sexual content. Still great, though.