The world is full of mysteries, from why anyone thought recreating emoji in real life was a good idea to what the heck is going on at Fushimi Inari Shrine. Another mystery is what all the digits of pi are. Since the number just goes on and on forever, it’s a mystery that will never — can never — be solved.

However, we have figured out a huge amount of pi — to trillions of digits, in fact! And you can even buy a book with the first one million digits in Japan thanks to the Dark Communications Group, which is not a group of mad mathematicians plotting to take over the world.

We hope.

The book pictured below is titled Pi to 1,000,000 Digits, as you probably already guessed. Originally published in 1996, the book was released by Ankoku Tsushin Dan, or the Dark Communication Group, which self-publishes the Pi book.


The book, which bears the recommended price of 314 yen (about US$2.50), apparently features 10,000 digits per page as well as the disclaimer that, while they’ve endeavored to get every single number correct, there may be mistakes. It provides a suggested method for using the book as a random number generator as well.

A simple FAQ section at the back also provides some information about the production of the unusual publication. According to it, the author developed an original program to derive the first million digits of pi in order to write the book. It’s also apparently not possible to copyright the digits of pi, which should be obvious, we suppose.

The Dark Communication Group has apparently also had some interesting communication with the Japanese National Library, including attempting to get a book wraparound alone included on the library’s shelves. Unfortunately, they got a rejection letter stating that the library would not accept books that consisted solely of wraparounds.

▼ The wraparound in question

The group is quite charitable with their creations though. In fact, we can all download wrapping paper with pi as a PDF for free! We bet it would be great for any graduating mathematicians you may know.

Pi isn’t the only number the Dark Communication Group cares about printing. They have also produced a memorization practice book for those seeming to get as many digits of pi into their brains as possible, plus books for e, used to find the natural logarithm of a number, and a list of 150,000 prime numbers.

In addition, the group has produced a number of other PDFs with everything from the square root of 2 to one million digits to the sine of 1 to one million digits. You can find those PDFs here, released under a creative commons license.

The books can be ordered online from their website or Amazon Japan, or bought at bookstores like Junkudo and Maruzen.


In case you’re wondering, the current record for finding the largest number of digits of pi is over 13.3 trillion digits, though Wikipedia tells us that for most practical purposes only the first 40 or so digits are generally necessary. The same entry also reveals memorizing pi is a common challenge people undertake (which is also apparently the main use of the book), with 67,890 digits the largest number of memorized digits confirmed by Guinness World Records.

We’re not sure what the use of knowing that many digits of pi is, but it certainly is impressive!

Sources: Naver Matome, Jin115, Darkside Communication Group, Wikipedia (Pi)
Image: Twitter (@aj1n)