I am not a mathematician. I am a novelist and short story writer who happens to love mathematics. I don't know mathematics on a deep level, but I like to think I'm well versed on the craft of story telling, and this is grade A.
I'm a little surprised that previous raters had an inverse evaluation than I did, giving the mathematical content over 4 on average, while the literary quality is somewhat less. The story is about a mathematician, yes, but although the math involved went sailing so far over my head that I barely heard the whistle, this in no way diminished my enjoyment of the story. Nor would any reader need to know any math at all to appreciate it. This, I think, speaks to its high literary quality. There is a certain timeless and universal appeal here, something that gets to the heart of what it means to be human, not just what it means to be a mathematician.
A frequent flaw with novice crafters of fiction is an attempt to make a protagonist an "everyman," a heavy-handed effort to artificially create that aforementioned universal appeal, and one almost inevitably doomed to fail.
What they learn, eventually, if they want to learn, is that the key to touching on our common humanity lies in specificity, not generality.
I was not surprised to learn that the story is essentially modeled on the ancient legend of Gilgamesh. There's a lot to be said for the old adage that there aren't any new stories, just new perspectives, interpretations, and presentations of old ones. This is an ideal example of precisely that.