90.222.124.190 at 17:28, 31 October 2014

2014-10-31T17:28:11Z

← Older revision		Revision as of 19:28, 31 October 2014
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	~~{{Infobox number~~		My name is Hershel from Vitriola doing my final year engineering in Computing and Information Science. I did my schooling, secured 78% and hope to find someone with same interests in Meteorology.<br><br>Feel free to surf to my page: how to get free fifa 15 coins ([http://Www.Radiojuliaca.Com.pe/index.php/el-collao/item/77-puno-centro-cultural-melodias-de-ilave-cu please click the following post])
	~~\| number = 121~~
	~~\| divisor = 1, 11, 121~~
	}}
	~~'''121''' ('''one hundred [and] twenty-one''')~~ is ~~the [[natural number]] following [[120 (number)\|120]]~~ and ~~preceding [[122 (number)\|122]]~~.

	~~==In mathematics==~~

	~~'''One hundred [and] twenty-one''' is a [[Square (algebra)\|square]]~~ and ~~is the sum of three consecutive [[prime number\|prime]]s (37 + 41 + 43). There are no squares besides 121 known~~ to ~~be of the form <math>1 + p + p^2 + p^3 + p^4</math>, where ''p'' is prime (3,~~ in ~~this case). Other such squares must have at least 35 digits~~.

	There are only two other squares known to be of the form n! + 1, supporting [[Brocard's conjecture]]. Another example of 121 being of the few examples supporting a conjecture is that Fermat conjectured that 4 and 121 are the only perfect squares of the form ''x''<~~sup~~>3<~~/sup~~> ~~- 4 (with ''x'' being 2 and 5, respectively).<ref>Wells, D., ''[[The Penguin Dictionary of Curious and Interesting Numbers]]'', London~~: ~~Penguin Group. (1987): 136</ref>~~

	~~It is also a [[star number]] and a [[centered octagonal number]].~~
	~~[[File:Chinese checkers start positions.svg\|thumb\|left\|A [[Chinese checkers]] board has 121 holes]]~~
	~~In base 10, it is a [[Smith number]] since its digits add up~~ to ~~the same value as its factorization (which uses the same digits) and as a consequence of that it is a [[Friedman number]]~~ (~~11^2). But it can not be expressed as the sum of any other number plus that number's digits, making 121 a [[self number]].~~

	~~==In other fields==~~

	~~121 is also:~~
	* The [[electricity]] [[emergency telephone number]] in [[Egypt]]
	* The number for [[voicemail]] for [[mobile phone]]s on the [[Vodafone]] network<ref>Vodafone, [http://~~www~~.~~vodafone~~.co.uk/~~business~~/~~mobile~~-~~phones~~/~~calling~~-~~and~~-~~messaging/ Calling and messaging]</ref>~~
	* The undiscovered [[chemical element]] [[Unbiunium]] has the ~~atomic number 121~~
	* The official end score for [[Cribbage]]<ref>[http://www.cribbage.org/rules/rule1.asp#section1 Rule 1.1]~~, [[American Cribbage Congress]], retrieved 6 September 2011</ref>~~

	~~==See also==~~
	* [[List of highways numbered 121]]
	* [[United States House of Representatives House Resolution 121]]
	* [[United Nations Security Council Resolution 121]]

	~~==References==~~

	~~<references/>~~

	~~{{Integers\|1}}~~

	~~{{DEFAULTSORT:121 (Number~~)}}
	~~[[Category:Integers]]~~

en>SmackBot: remove Erik9bot category,outdated, tag and general fixes

2009-12-16T11:41:15Z

remove Erik9bot category,outdated, tag and general fixes

New page

{{Infobox number
| number = 121
| divisor = 1, 11, 121
}}
'''121''' ('''one hundred [and] twenty-one''') is the [[natural number]] following [[120 (number)|120]] and preceding [[122 (number)|122]].

==In mathematics==

'''One hundred [and] twenty-one''' is a [[Square (algebra)|square]] and is the sum of three consecutive [[prime number|prime]]s (37 + 41 + 43). There are no squares besides 121 known to be of the form <math>1 + p + p^2 + p^3 + p^4</math>, where ''p'' is prime (3, in this case). Other such squares must have at least 35 digits.

There are only two other squares known to be of the form n! + 1, supporting [[Brocard's conjecture]]. Another example of 121 being of the few examples supporting a conjecture is that Fermat conjectured that 4 and 121 are the only perfect squares of the form ''x''<sup>3</sup> - 4 (with ''x'' being 2 and 5, respectively).<ref>Wells, D., ''[[The Penguin Dictionary of Curious and Interesting Numbers]]'', London: Penguin Group. (1987): 136</ref>

It is also a [[star number]] and a [[centered octagonal number]].
[[File:Chinese checkers start positions.svg|thumb|left|A [[Chinese checkers]] board has 121 holes]]
In base 10, it is a [[Smith number]] since its digits add up to the same value as its factorization (which uses the same digits) and as a consequence of that it is a [[Friedman number]] (11^2). But it can not be expressed as the sum of any other number plus that number's digits, making 121 a [[self number]].

==In other fields==

121 is also:
* The [[electricity]] [[emergency telephone number]] in [[Egypt]]
* The number for [[voicemail]] for [[mobile phone]]s on the [[Vodafone]] network<ref>Vodafone, [http://www.vodafone.co.uk/business/mobile-phones/calling-and-messaging/ Calling and messaging]</ref>
* The undiscovered [[chemical element]] [[Unbiunium]] has the atomic number 121
* The official end score for [[Cribbage]]<ref>[http://www.cribbage.org/rules/rule1.asp#section1 Rule 1.1], [[American Cribbage Congress]], retrieved 6 September 2011</ref>

==See also==
* [[List of highways numbered 121]]
* [[United States House of Representatives House Resolution 121]]
* [[United Nations Security Council Resolution 121]]

==References==

<references/>

{{Integers|1}}

{{DEFAULTSORT:121 (Number)}}
[[Category:Integers]]

Isomorphism of categories - Revision history

90.222.124.190 at 17:28, 31 October 2014

en>SmackBot: remove Erik9bot category,outdated, tag and general fixes