View source for Repdigit

==English==
{{was wotd|2018|August|20}}
[[File:Washington, D.C. license plate, 2011.jpg|thumb|The number 7777 on this [[Washington, D.C.]], vehicle [[license plate]] is a repdigit]]

===Etymology===
{{blend|en|repeated|alt1=rep(eated)|digit}}.

===Pronunciation===
* {{IPA|en|/ˈɹɛpˌdɪd͡ʒɪt/|a=RP,GA}}
** {{audio|en|LL-Q1860 (eng)-Vealhurl-repdigit.wav|a=Southern England}}
* {{hyphenation|en|rep|di|git}}

===Noun===
{{examples|width=10%|examples=* 7
* 11
* 666
* 9,999}}
{{en-noun}}

# {{lb|en|recreational mathematics}} A [[number#Noun|number]] [[compose]]d only of one or more occurrences of one specific [[digit]] and no other digit.
#* {{quote-journal|en|author=David W. Ballew; Ronald C. Weger|title=Repdigit Triangular Numbers|journal=w:Journal of Recreational Mathematics|location=Farmingdale, N.Y.|publisher=Baywood Publishing Co.|year=1975|volume=8|issue=2|pages=96–98|issn=0022-412X|oclc=951131554|passage='''Repdigit''' Triangular Numbers [article title]}}
#* {{quote-journal|en|author=[[w:Murray S. Klamkin|Murray S[eymour] Klamkin]]|quotee=Charles W. Trigg|title=The Olympiad Corner: 11|journal=w:Crux Mathematicorum|location=Ottawa, Ont.|publisher=w:Canadian Mathematical Society|month=January|year=1980|volume=6|issue=1|page=16|issn=0705-0348|oclc=477103351|passage=Is there any system of notation in which there is a '''repdigit''' <math>aa</math> such that <math>(aa)^2 = ccdd</math>, with <math>c = a - 1</math> and <math>d = c - 1</math>?}}
#* {{quote-book|en|author=[[w:Clifford A. Pickover|Clifford A[lan] Pickover]]|chapter=Gallery I: Squares, Cubes, and Tesseracts|title=The Zen of Magic Squares, Circles, and Stars: An Exhibition of Surprising Structures across Dimensions|location=Princeton, N.J.; Woodstock, Oxfordshire|publisher=w:Princeton University Press|year=2002|page=284|pageurl=https://books.google.com/books?id=slpObYbvV4gC&pg=PA284|isbn=978-0-691-07041-4|passage=Here is another palindromic magic square that has the added property of having main diagonals containing eight repeating "'''repdigits'''": 222, 333, 444, 555, 666, 777, 888, and 999. The magic sum is 2442.}}
#* {{quote-book|en|author=James J[oseph] Tattersall|chapter=Modular Arithmetic|title=Elementary Number Theory in Nine Chapters|edition=2nd|location=Cambridge|publisher=w:Cambridge University Press|year=2005|section=section 5.6 (Supplementary Exercises), paragraph 14|page=193|pageurl=https://books.google.com/books?id=QGgLbf2oFUYC&pg=PA181-IA1|isbn=978-0-521-85014-8|passage=A positive with repeated digit is called a '''repdigit''', for example 222, 55555, and all repunits are '''repdigits'''.}}

====Hyponyms====
* {{l|en|repunit}}

====Translations====
{{trans-top|number composed of one digit}}
* Bulgarian: {{t|bg|репдиджит}}
* Chinese:
*: Mandarin: {{t|cmn|純位數|tr=chúnwèishù}}
* Esperanto: {{t|eo|repdigito}}
* French: {{t|fr|nombre uniforme|m}}
* German: {{t+|de|Schnapszahl|f}}
* Italian: {{t|it|numero a cifra ripetuta|m}}
* Japanese: {{t|ja|ぞろ目}}
* Korean: {{t|ko|렙디지트}}
* Russian: {{t|ru|репди́гиты}}
* Tamil: {{t|ta|ஒற்றெண்}}
{{trans-bottom}}

====See also====
* {{l|en|repeating decimal}}
* {{l|en|repetend}}

===References===
* {{cite-web|author=Eric W[olfram] Weisstein|authorlink=Eric W. Weisstein|title=Repdigit|url=http://mathworld.wolfram.com/Repdigit.html|archiveurl=https://web.archive.org/web/20180215010545/http://mathworld.wolfram.com/Repdigit.html|archivedate=15 February 2018|work={{w|MathWorld}}|accessdate=20 August 2018}}.

===Further reading===
* {{pedia}}