Hardcover · 17 September 2026
A big
prime
number
43 × 2835934 + 1 · 251,643 digits
One email on publication day, nothing else. Or ask any bookshop for ISBN 979-8-9975417-0-5.
This is a book about one number. A specific number. A number with 251,643 digits, no factors worth mentioning, and — if the cover is to be believed — its own gravitational field.
All of it is printed, set like a novel, which took a hundred and fifty pages and a certain amount of explaining to people. Read aloud at two digits a second it runs about thirty-five hours.
Between the digits are 43 true stories. Each begins in real mathematics and does not stop there — it keeps going, past the proof and into the person it happened to. A duel at dawn. A serial killer's cipher. A bug that cost Intel half a billion dollars. A prisoner, a monk, a teenager, a spy.
The number was prime before the Earth was here and nothing has happened to it since. This is very possibly the first time anyone has laid it out whole, for a pair of human eyes.
- Format
- Hardcover with dust jacket
- Extent
- 282 pages, 6 x 9 in
- Of which
- 150 pages are the number itself
- Price
- $34.99 US · $43.97 CAN
- ISBN
- 979-8-9975417-0-5
- Publisher
- Long Weekend Books, Austin, Texas
- Published
- 17 September 2026
Who wrote it
Jason Probert grew up outside Detroit, went to Wharton, and has spent his career in business — an investor, owner and operator in an industry built on buildings, leases and spreadsheets. He is not a mathematician. The last formal math he did was in service of a business degree.
He started this book as a gift for his college roommate, and it got away from him. He is a member of the Great Internet Mersenne Prime Search, and as you read this a computer in his office is testing a number thousands of times larger than the one in your hands. The odds it finds anything are almost exactly zero. This changes nothing.
A note for the patient
The number was not typeset as innocently as it pretends. Nothing else will be said about that here.