101 (one hundred [and] one) is the natural number following 100 and preceding 102. It is variously pronounced "one/a hundred and one", "one/a hundred one", and "one oh one".
In mathematics
101 is the 26th prime number and a palindromic number (and so a palindromic prime). The next prime is 103, with which it comprises a twin prime, making 101 a Chen prime. Because the period length of its reciprocal is unique among primes, 101 is a unique prime. 101 is an Eisenstein prime with no imaginary part and real part of the form 3n − 1.
101 is the sum of five consecutive primes (13 + 17 + 19 + 23 + 29). Given 101, the Mertens function returns 0. 101 is the fifth alternating factorial.
101 is a centered decagonal number.
For a 3-digit number in base 10, this number has a relatively simple divisibility test. The candidate number is split into groups of four, starting with the rightmost four, and added up to produce a 4-digit number. If this 4-digit number is of the form 1000a + 100b + 10a + b (where a and b are integers from 0 to 9), such as 3232 or 9797, or of the form 100b + b, such as 707 and 808, then the number is divisible by 101. This might not be as simple as the divisibility tests for numbers like 3 or 5, and it might not be terribly practical, but it is simpler than the divisibility tests for other 3-digit numbers.
On the seven-segment display of a calculator, 101 is both a strobogrammatic prime and a dihedral prime.
In science
- In mineralogy, a Miller index of 101 is a crystal face that crosses the horizontal axis (a) and 3d vertical axis (c) but does not cross the 2d vertical axis (b).
- In physics and chemistry, the atomic number of mendelevium, an actinide.
In transportation
Buildings
In radio
In books
- According to Books in Print, more books are now published with a title that begins with '101' than '100'. They usually describe or discuss a list of items, such as 101 Ways to... or 101 Questions and Answers About... . This marketing tool is used to imply that the customer is given a little extra information beyond books that include only 100 items. Some books have taken this marketing scheme even further with titles that begin with '102', '103', or '1001'. The number is used in this context as a slang term when referring to "a 101 document" what is usually referred to as a statistical survey or overview of some topic.
- Room 101 in George Orwell's novel Nineteen Eighty-Four.
- The 101 Ranch written by Ellsworth Collings in collaboration with Alma Miller England, narrates the history of the Miller Brothers 101 Ranch
- The Hundred and One Dalmatians, or "The Great Dog Robbery" is a 1956 children's novel by Dodie Smith
- 101 Philosophy Problems and 101 Ethical Dilemmas, both by Martin Cohen, are two introductions to philosophy that playfully adapt the friendly '101' marketing concept for a more serious pedagogical purpose.
- The Professors: The 101 Most Dangerous Academics in America is a 2006 book by David Horowitz
- The Secret Agent on Flight 101 is Volume 46 in the original The Hardy Boys book series
- According to the New Oxford American Dictionary "101" is an adjective, describing a course of education, either imagined or real, in basic knowledge. For example "stuff that you should learn in Anatomy 101"
In film
In music
In television
In sport
Other uses
- Beijing 101
- 101 Ranch Oil Company
- 101st kilometre, a condition of release from the Gulag in the Soviet Union.
- Unit 101 of the Israeli Defense Forces.
- An HTTP status code indicating that a client should switch protocols (e.g. to HTTPS).
- The first course in a subject taught at a college or university in Australia, Canada, South Africa, or the United States. By extension, "Topic 101" is used generallly to indicate the basics of any subject. This expression is not used in the UK.[1] Used this way, it is always pronounced "one-oh-one".[2][3]
- For a new checking account in the US, the number of the first check.
- A term used to define the number of keys on a computer keyboard[4]
- The 101st Airborne Division (Air Assault) — nicknamed the "Screaming Eagles" — an airborne division of the United States Army primarily trained for air assault operations.
- The Crusader 101, an electrically-operated toy car.
- An emergency telephone number in Argentina, Belarus, Belgium, India, and Israel.
- The One Hundred First United States Congress met from January 3, 1989 to January 3, 1991 during the first two years of the President George H. W. Bush administration
- The Single Non-Emergency Number (SNEN), a telephone number being rolled out in the United Kingdom for telephone calls to services that are urgent but not emergencies.[5]
See also
References
- Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): page 133. ISBN 978-0140080292
- ^ Engber, Daniel (6 September 6, 2006), ""101 101: How did intro classes get their trademark number?", Slate, http://www.slate.com/id/2149082/
- ^ 101, Dictionary.com, http://dictionary.reference.com/search?q=101
- ^ At universities with four-digit course numbers, the equivalent course number is 1001 or 1010. This use is unheard of in the United Kingdom.
- ^ 101-Key "Enhanced" Keyboard Layout, PC Guide, http://www.pcguide.com/ref/kb/layout/stdEnh101-c.html, retrieved on 2009-05-04
- ^ Welcome to 101, Home Office, http://www.101.gov.uk, retrieved on 2009-04-05
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)