# From Zero to Infinity: 27 Remarkable Math Facts

## 1Belphegor's Prime

Belphegor's Prime is a prime number that is also a palindrome. It's named after the Prince of Hell for ingenious inventions because it contains two sets of 13 zeroes with 666 in the center. The palindromic prime number is 1000000000000066600000000000001.

## 2Illegal prime

There are prime numbers (Illegal prime) that are illegal to possess or distribute. One of the first ones, found in 2001, was used to bypass copyright protection on DVDs.

## 3Yitang Zhang

A Chinese mathematician named Yitang Zhang could not get an academic job upon graduating, having to work as an accountant and a delivery worker for a New York City restaurant. He later went on to solve a math problem that had been unsolved for 150 years and won a MacArthur Genius Grant.

## 4Roulette wheel

The sum of all numbers on a roulette wheel is 666.

## 5Millihelen

Mathematicians have jokingly proposed a standard unit of measurement for beauty called the “millihelen.” Inspired by Helen of Troy, a millihelen is defined as “the amount of beauty required to launch one ship.”

## 6Dunbar's number

The Dunbar's number is a theoretical upper limit of the people one can maintain stable relationships with. It is suggested between 100 and 250. So if a town's population is below the Dunbar's number, it is more likely to have harmony and peace than a larger town or city.

## 7Odd number

The sum of odd numbers starting at 1 is always a square number.

## 8Roman numerals

I, V, X, L, C, D, M aren't the only letters used in Roman numerals; "S" is used to represent ½ along with dots for other fractions.

## 9142,857

The number 142,857, when multiplied by 1,2,3,4,5, or 6, is an anagram of itself. The fractions 1/7 through 6/7 also are forms of 142857, and the right six digits of any higher multiple plus the remaining left digits will equal an anagram of 142857.

## 10Fibonacci sequence

The inverse of 999,999,999,999,999,999,999,998,999,999,999,999,999,999,999,999 gives the fibonacci sequence in 24 digit strings.

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