In the past few years, I’ve seen books written about lots of different things like elements, molecules, and colors. I’m surprised that no one has written a biography of numbers.

Math nerds like me would love this book. I’m thinking it would look like Elements: A Visual Exploration of Every Known Atom in the Universe. Each page would have a fancy drawing of the number with some text. For Example:

The text would look something like below. Most of the text here comes from 42’s Wikipedia page (yes, 42 has a Wikipedia page)

- Popular Culture:
- The jersey number of Jackie Robinson, which is the only number retired by all Major League Baseball teams. It was also the name of a Jackie Robinson biopic.
- In The Hitchhiker’s Guide to the Galaxy by Douglas Adams, 42 is the “Answer to the Ultimate Question of Life, the Universe, and Everything.” Unfortunately, no one knows what the question is. Thus, to calculate the Ultimate Question, a special computer the size of a small planet was built from organic components and named “Earth.” Earth calculated the Ultimate Question to be “What do you get when you multiply six by nine.”
^{}The 2011 book 42: Douglas Adams’ Amazingly Accurate Answer to Life, the Universe and Everything^{}examines Adams’ choice of the number 42, and contains a compendium of some instances of the number in science, popular culture, and humor.

- Science and Technology:
- 42 is the atomic number of molybdenum.
- 42 minutes is the time it takes to travel through the earth on a gravity train, a hypothetical system for traveling through the core of the earth via a vacuum tube.
- Messier object M42, is the formal name of the Orion Nebula.
- In January 2004, asteroid 2001 DA
_{42}was given the permanent name 25924 Douglasadams, for the author Douglas Adams. Brian G. Marsden, the director of the Minor Planet Center and the secretary for the naming committee, remarked that, with even his initials in the provisional designation, “This was sort of made for him, wasn’t it?”.

- Some interesting mathematical facts about 42. Here are a few of the ones I could understand:
- Forty-two (42) is a pronic number
^{}(product of two consecutive integers) and an abundant number (the sum of its factors is larger than the number) - Its prime factorization 2 · 3 · 7 makes it the second sphenic number and also the second of the form (2 · 3 ·
*r*). - 42 is the sum of the first 6 positive even numbers.
- 42 is the resulting number of the original Smith number (4937775 = 3 × 5 × 5 × 65837): Both the sum of its digits (4 + 9 + 3 + 7 + 7 + 7 + 5) and the sum of the digits in its prime factorization (3 + 5 + 5 + (6 + 5 + 8 + 3 + 7)) result in 42.
- The numbers 1 to 27 can form a 3 × 3 × 3 magic cube such that every row, column, and corridor, and every diagonal passing through the center, is composed of 3 numbers whose sum of values is 42.

- Forty-two (42) is a pronic number

Unfortunately, the quality of Wikipedia pages varies and I haven’t seen any others as good as 42. Here are some other facts I’d add to the book:

**4.**The only number that has its own number of letters.**7.**- This page has a lot of good facts about the number 7 including the fact that of the first 10 numbers, seven is the only one that you cannot multiply or divide it within the group. It feels the most unique.
- According to one study, 7 is the most common favorite number, with 10% voting for it.
- Seven was seen as a sacred number in Issac Newton’s times. When examining the colors of the rainbow, Newton labeled the colors as Red, Orange, Yellow, Green, Blue, Indigo, and Violet. The only reason Indigo was included was to raise the number to seven.

**9.**- Cats are said to have nine lives.
- Greeks saw 9 as a magic number, referring to it as “the trinity of trinities.”
- The digits in any multiple of 9 always add up to a multiple of 9.

**23.**The minimum number of people at a party such that there is at least a 50% chance that two will have the same birthday.**40.**The number 40 is found in many traditions without any universal explanation for its use. In Jewish, Christian, Islamic, and other Middle Eastern traditions it is taken to represent a large, approximate number, similar to “umpteen“.

And then you’d need a special section with special numbers like 0, π, e, the golden ratio, i, and all those other fun ones that math geeks love. I found a good site called Archimedes Lab with some fun facts about these special numbers.

I really like this idea but will never actually create the book. I hope someone else does though! And until then, tell me what other numbers you like.