|
|
| Line 1: |
Line 1: |
| {{for|the card game|Twenty-eight (card game)}}
| | Dalton is what's written for his birth certificate remember, though , he never really enjoyed reading that name. His friends say it's unhealthy for him but alternatives he loves doing typically is acting and he's been doing it for quite a while. In your [http://boyfriendsprofessional.com boyfriend's professional] life he is a filing assistant and after that his salary has been really fulfilling. His wife and my man live in Idaho in [http://mondediplo.com/spip.php?page=recherche&recherche=addition addition] he needs to glide because of his relative. Go to his website acquire out more: http://circuspartypanama.com<br><br>my web blog :: [http://circuspartypanama.com clash of clans hack tools] |
| {{Infobox number
| |
| | number = 28
| |
| | divisor = 1, 2, 4, 7, 14, 28
| |
| }}
| |
| '''28''' ('''twenty-eight''') is the [[natural number]] following [[27 (number)|27]] and preceding [[29 (number)|29]]. | |
| | |
| There are also 28 days in February unless it is a leap year.
| |
| ==In mathematics==
| |
| It is a [[composite number]], its proper [[divisor]]s being [[1 (number)|1]], [[2 (number)|2]], [[4 (number)|4]], [[7 (number)|7]], and [[14 (number)|14]].
| |
| | |
| Twenty-eight is the second [[perfect number]]. As a perfect number, it is related to the [[Mersenne prime]] 7, since 2<sup>2</sup>(2<sup>3</sup> - 1) = 28. The next perfect number is [[496 (number)|496]], the previous being [[6 (number)|6]].
| |
| | |
| Twenty-eight is the third [[Granville number]]. The next Granville number is [[96 (number)|96]], the previous being [[24 (number)|24]].
| |
| | |
| Twenty-eight is the sum of the [[totient function]] for the first nine integers.
| |
| | |
| Twenty-eight is not the [[aliquot sum]] of any number other than itself and is therefore not a component in an [[aliquot sequence]].
| |
| | |
| Since the greatest [[prime factor]] of 28<sup>2</sup> + 1 = 785 is 157, which is more than 28 twice, 28 is a [[Størmer number]].
| |
| | |
| Twenty-eight is a [[harmonic divisor number]], a [[happy number]], a [[triangular number]], a [[hexagonal number]], and a [[centered nonagonal number]].
| |
| | |
| It appears in the [[Padovan sequence]], preceded by the terms 12, 16, 21 (it is the sum of the first two of these).
| |
| | |
| It is also a [[Keith number]], because it recurs in a [[Leonardo of Pisa|Fibonacci]]-like sequence started from its base 10 digits: 2, 8, 10, 18, 28...
| |
| | |
| Twenty-eight is the third positive integer with a prime factorization of the form <math>2^2 q</math> where ''q'' is an [[odd prime]].
| |
| | |
| Twenty-eight is the ninth and last number in early [[India]]n [[magic square]] of order 3.
| |
| | |
| There are twenty-eight [[convex uniform honeycomb]]s.
| |
| | |
| Twenty-eight is the only positive integer that has a unique [[Kayles]] [[nim-value]].
| |
| | |
| ==In science==
| |
| * The [[atomic mass]] of [[silicon]].
| |
| * The [[atomic number]] of [[nickel]].
| |
| * The fourth [[Magic number (physics)|magic number]] in physics.
| |
| * The [[curing time]] of [[concrete]] is classically considered 28 days.
| |
| * The average human [[menstrual cycle]] is 28 days although no link has been established with the [[Menstrual_cycle#Nightlighting_and_the_moon|nightlighting and the Moon]].
| |
| | |
| ==Astronomy==
| |
| | |
| * The revolution time of the surface of the [[Sun]] on itself is 28 days while its core is revolving in 33 days.<ref>[http://news.stanford.edu/news/2010/august/sun-082310.html Stober D. (2010) The strange case of solar flares and radioactive elements].</ref>
| |
| | |
| * [[Messier object]] [[Messier 28|M28]], a [[visual magnitude|magnitude]] 8.5 [[globular cluster]] in the [[constellation]] [[Sagittarius (constellation)|Sagittarius]].
| |
| | |
| * The [[New General Catalogue]] [http://www.ngcic.org/ object] [[NGC 28]], an [[elliptical galaxy]] in the constellation [[Phoenix (constellation)|Phoenix]].
| |
| | |
| * The [[Saros number|Saros]] [http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html number] of the [[solar eclipse]] series which began on [[-1910]] March 22 and ended on [[-630]] April 28. The duration of Saros series 28 was 1280.1 years, and it contained 72 solar eclipses.
| |
| | |
| * The Saros [http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html number] of the [[lunar eclipse]] series which began on [[-1915]] June 27 and ended on [[-581]] September 6. The duration of Saros series 28 was 1334.2 years, and it contained 75 lunar eclipses.
| |
| <!-- | |
| ==In sports==
| |
| Retired jersey numbers, numbers stated in the rules of the game, major league statistics go here -->
| |
| | |
| ==In sports==
| |
| *The jersey number 28 has been retired by several [[Major professional sports leagues in the United States and Canada|North American sports]] teams in honor of past playing greats or other key figures:
| |
| ** In [[Major League Baseball]]:
| |
| *** The [[Minnesota Twins]], for [[National Baseball Hall of Fame and Museum|Hall of Famer]] [[Bert Blyleven]].
| |
| ** In the [[National Football League|NFL]]:
| |
| *** The [[Chicago Bears]], for [[Willie Galimore]].
| |
| *** The [[Kansas City Chiefs]], for [[Abner Haynes]].
| |
| *** The [[New York Jets]], for [[Pro Football Hall of Fame|Hall of Famer]] [[Curtis Martin]].
| |
| *** The [[St. Louis Rams]], for Hall of Famer [[Marshall Faulk]].
| |
| * The [[National Basketball Association|NBA]] and [[National Hockey League|NHL]] both operate four best-of-seven rounds during the playoffs; thus, 28 is the maximum number of games that a team could possibly play in the playoff series (neither league has ever had a team play that many games, though).
| |
| * The number worn by the Clemson Tigers' record breaking running back [[C.J. Spiller]], former Colts and Rams running back Marshall Faulk, former Bucs and Falcons running back Warrick Dunn, former Kansas City Chiefs running back [[Abner Haynes]], current Titans running back Chris Johnson.
| |
| * The number of a car formerly run in the [[NASCAR]] [[Sprint Cup Series]] by [[Yates Racing]]. The most notable driver of the #28 was [[Davey Allison]], who had the ride for his entire Cup Series career.
| |
| | |
| ==In other fields==
| |
| '''Twenty-eight''' is:
| |
| * An abbreviation for such years as 1928 and 2028.
| |
| * In [[Gematriya]], the system of Hebrew [[Numerology]], ''koakh'', meaning "power", "energy" is a word that corresponds to the number 28.
| |
| * The number of Hebrew letters in Genesis 1:1, the first verse of the Bible.
| |
| * The number of wheels on a [[Lockheed C-5 Galaxy]].
| |
| * In the [[code for international direct dial]] phone calls, +28 is unassigned.
| |
| * 028 is the [[ISO 3166-1]] numeric 3 digit country code for [[Antigua and Barbuda]].
| |
| * The number of days in the shortest [[month]] of the [[Gregorian calendar]], [[February]] (except in [[leap year]]s, when there are twenty-nine). All twelve months of the Gregorian calendar have at least 28 days, regardless of the year.
| |
| * The [[Gregorian calendar]] follows a 28-year cycle for the most part, since there are seven days in a week and leap year generally occurs every four years; usually, a calendar from any year is the same as that from 28 years earlier (e.g., 2008 and 1980 or 2009 and 2037). However, that rule holds only when there have been exactly seven leap days in a 28-year interval; years divisible by 100 but not by 400 are not leap years. Indeed, 1900 (as well as 2100, 2200, etc.) does not use the same calendar as 1872 (2072, 2172, etc., respectively) for the simple reason that 1900 is not a leap year. In 28 years, any day-of-the-week and date combination occurs exactly four times. February 29 will fall on each day of the week once.
| |
| * In Jewish tradition there is a 28 year [[Solar cycle (calendar)|solar cycle]] in which the sun returns to its place in [[Genesis creation narrative|Creation]] every 28 solar years. This is commemorated in April every 28 years with the recitation of ''[[Birkat Hachama]]'', the blessing of the sun.
| |
| * The common name for the [[parrot]] [[Australian Ringneck|'Barnardius zonarius semitorquatus']], widely distributed in [[Western Australia]] and [[South Australia]]. Its call sounds like "wenniate".
| |
| * The number of letters in the [[Danish alphabet|Danish]] and [[Swedish alphabet|Swedish]] [[alphabet]]s (not counting W), and also in the [[Arabic alphabet|Arabic]] and [[Esperanto orthography|Esperanto]] [[alphabet]]s.
| |
| * In neo-Nazi circles, twenty-eight indicates [[Blood and Honour]] (28 = BH - B - second letter of the alphabet and H - the eight letter).
| |
| * The number of [[Chinese constellations]], "Xiu" or "mansions" (a literal translation), equivalent to the 12 western [[zodiac]] constellations.
| |
| * The number of [[dominoes]] in standard domino sets.
| |
| * Deriving from the 29.46 year period of [[Saturn]]'s revolution around the [[Sun]], the 28-year cycle as well as its subdivisions by 14 and 7 are supposed in [[Astrology]] to mark significant turning points or sections in the course of a persons development in life. Thus, the number 28 has special significance in the culture of religious sects such as the [[Kadiri]] and the [[Mevlevi]] dervishes. The 28-beat metric pattern often used in the music compositions accompanying the main part of the [[Mevlevi]] [[sema]] ritual is called the "Devri kebir", meaning the "Big Circle" and is a reference to above astronomical facts about the year and the Saturn year.
| |
| * In [[Quebec]], [[François Pérusse]], in one of his best-selling [[Album du peuple]] made a parody of [[Wheel of Fortune (U.S. game show)|Wheel of Fortune]] in which all of the letters picked by the contestant were present 28 times. As a result, 28 became an almost [[Mythical number]] used by many Quebec youths, the phrase "Y'en a 28" (There are 28 [Letters]) became a [[running gag]] still used and recognized more than 15 years later.
| |
| * The [[Preludes Op. 28 (Chopin)|Preludes, Opus 28]] consists of [[Frédéric Chopin]]'s 24 preludes for piano, ordinarily but not necessarily played together in concert.
| |
| * The [[postal code]] of the [[Community of Madrid|province of Madrid]], in [[Spain]].
| |
| * [[Twenty-eight (card game)|Twenty Eight]] is a popular game played in Kerala, India.
| |
| * The number of the French department [[Eure-et-Loir]].
| |
| * Approximately the number of grams in an ounce, and used as such in the illegal drug trade.
| |
| * The [[UIC Country Code]] for [[Georgia (country)|Georgia]] identifying member countries of the [[International Union of Railways]] (UIC).
| |
| * The letter ''[[Q]]'' when encoding the serial number for [[intermodal containers|intermodal (shipping) containers]] as defined by [[ISO 6346]].
| |
| | |
| ==References==
| |
| <references/>
| |
| * [http://primes.utm.edu/curios/page.php/28.html Prime Curios! 28] from the [[Prime Pages]]
| |
| | |
| {{Integers|zero}}
| |
| | |
| [[Category:Integers|2 8]]
| |