“Ulysses,” it ain’t. And why, you may ask, do I start by saying what this book is not? Because Joshua Cohen’s startling new 580-page novel, “Book of Numbers” (Random House), reads like James Joyce’s giant classic — and that’s not necessarily a bad thing. Wordy, to a fault — yes, and dense. But Cohen’s prose is dazzling, often magical. It’s not just the polymathic command of his subject matter — and Cohen is a polymath of art history, and computers, and comparative religion, and seemingly everything else. He is a master wordsmith of wordplay.

Yet, “Book of Numbers” is a mess, and worse: it’s a massive circuit overload. And still, the book hums along. The reader eagerly awaits the next paragraph, the next line, the next strange locution, the next neologism, the next bizarre footnote, the next weird character…

With “Book of Numbers,” his fourth novel, Joshua Cohen has emerged not only as a significant American writer but perhaps as a major literary voice. His new novel will stand as one of the impressive novels of the decade.

So what’s it all about?

The novel’s plot is deceptively simple: on the surface, it is about Joshua Cohen (yes, he is Josh Cohen), who signs on to ghostwrite the biography of the genius founder of Tetration, the world’s monster tech company. The novel may be the high-tech thriller that it is, but in the end more like, “Boy meets binary code, boy loves binary code, boy loses binary code, boy gets binary code.”

But not so fast. Who is “Joshua Cohen?” There are at least two Joshua Cohens in “Book of Numbers.” One is the struggling writer, a stalled, writer’s-block-plagued Jewish novelist — he researched for years a yawner about his mother’s escape from Nazi-occupied Poland — “with a humanities diploma between my legs and not enough arm to reach the Zohar.” That Cohen is reduced to writing (uhh) reviews to make a living. He has ambition, and envy, and a pornography addiction. The other Joshua Cohen is the billionaire tech genius. Get it?

Digression after digression takes us to the core of the story: a mind-bending journey that pushes Josh-the-failed-writer toward an understanding of the sinister motive behind the autobiography project. In order to count as a thriller, the stakes have to be high, and there is none higher than the life-and-death antics that surround the creating and publication of the biography. Yes, “Book of Numbers” is a thriller.

But “Book of Numbers” is also a truly funny book — and it’s not only Joshua Cohen’s turns-of-phrase that make it so. The book is to be read (if I am getting it right — and with this book one never knows) as a comic novel as well as techno-thriller — and at the same time as a moral screed. The billionaire creator of Tetration muses about the horrors of search engines and their effect, ultimately, on humanity and humankind. “A spouse would seek advice on infidelity from a different calc. How to hide a body. Consulting linear algebra on how to terminate a pregnancy.” And, most of all: “Breathe greedy!”

And of course, much will be made of Joshua Cohen’s opening line, “If you’re reading this on a screen, f— off.”

The humor of “Book of Numbers” is most evident in the long middle section of the book, which is a polyphonic point-counterpoint — it’s a Bach fugue; the listener can’t quite get there — between the two Joshes, the billionaire and the narrator, balding and schleppy and brilliant Josh.

Brilliant, and funny, to be sure, but there is something off, something annoying, about Cohen’s narrative sense. Joshua Cohen the author gets carried away, indeed loses control, over his two fictional Joshes (and as a result over his novel) in the extended middle section of the book. Josh the billionaire is simply not the character that Josh the failed novelist is. It is as if the author has lost track of his characters; or, he does not want to reader to be invested in the billionaire. Whatever — the reader will nod off after a hundred or so pages of the Tetration story. A problem here with the editor’s blue pencil? Perhaps. There is too much data, too many “numbers,” in “Book of Numbers,” and not enough tachlis. At a crucial juncture, “Book of Numbers” simply stalls. What are numbers all about?

All of which leads us to the other “Book of Numbers,” the fourth of the Chumashim in the Hebrew Scripture. The eponymous “numbers” in the Chumash are those of the counting of the Israelites, both a religious obligation and as a means of raising the revenue necessary for the maintenance of the polity. But numbers as a religious obligation is a serious matter. Elsewhere in the Tanach, the Hebrew Bible, inappropriate counting of Israelites is fraught with peril — indeed, if not done with Divine sanction, with mortal peril. Joshua Cohen the author — and Josh Cohen the writer — are well aware of the boons and perils of numbers. They are about ethics, and ultimately about mortality.

“Book of Numbers” is about being a human in the age of the computer. A tough proposition, that. Ethicists, historians, rabbis and priests — take note!

Jerome A. Chanes writes about arts and letters and about American Jewish public affairs and history. He is the author of four books and is a fellow at the Center for Jewish Studies at the CUNY Graduate Center.