101 (one hundred [and] one) is the natural number following 100 and preceding 102. It is variously pronounced "one hundred and one," "a hundred and one," "one hundred one," or colloquially "one oh one."
Mathematical Properties
- 101 is a prime number and the smallest integer above 100. It is the 26th prime number.
- It is a palindromic number (reads the same forwards and backwards) and, consequently, a palindromic prime.
- It is an alternating factorial and a sexy prime.
- 101 is the smallest number that can be expressed as the sum of three distinct nonzero squares in more than two ways: 9² + 4² + 2², 8² + 6² + 1², and 7² + 6² + 4².
- As an ordinal number, 101st (one hundred [and] first), rather than 101th, is the correct form.
Cultural and Practical Usage
Academic Course Numbering
In American university course numbering systems, 101 is widely used to denote an introductory course at a beginner's level in a department's subject area (e.g., "Biology 101," "English 101"). This numbering convention was designed to facilitate transfer between colleges. One of the earliest recorded uses was by the University of Buffalo in 1929. Based on this, the term "101" has entered slang usage to refer to basic knowledge of a topic, as in "Cooking 101." The Oxford English Dictionary records this slang sense from 1986.
Publishing
According to Books in Print, more book titles begin with "101" than with "100," often in formats such as 101 Ways to... or 101 Questions and Answers About..., implying the reader receives something extra beyond 100 items.
Literature
In George Orwell's Nineteen Eighty-Four, Room 101 is a torture chamber in the Ministry of Love where victims confront their deepest fears.
Other Notable References
- 101 is a lucky number in Hinduism.
- 101 is the police emergency number in Belgium and the Single Non-Emergency Number (SNEN) in parts of the United Kingdom.
- 101 is an HTTP status code indicating that the server is switching protocols.
- Taipei 101 was the tallest skyscraper in the world from 2004 to 2010.
- Mendelevium (Md) is the chemical element with atomic number 101.
- U.S. Route 101 is a major highway along the West Coast of the United States.
- 101st Airborne Division is a renowned U.S. Army division.
- 101 Dalmatians is a popular Disney franchise based on Dodie Smith's novel.
- Bill 101 (Charter of the French Language) is a landmark language law in Quebec, Canada.
- Room 101 in Nineteen Eighty-Four has spawned numerous references in television and media.
