218 (two hundred
ndeighteen) is the
natural number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country").
Numbers used for counting are called ''Cardinal n ...
following
217
Year 217 (Roman numerals, CCXVII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Praesens and Extricatus (or, less frequently, yea ...
and preceding
219
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Year 219 ( CCXIX) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Antonius and Sacerdos (or, less frequently, year 972 '' ...
.
In mathematics
*
Mertens function
In number theory, the Mertens function is defined for all positive integers ''n'' as
: M(n) = \sum_^n \mu(k),
where \mu(k) is the Möbius function. The function is named in honour of Franz Mertens. This definition can be extended to positive r ...
(218) = 3, a record high.
*218 is
nontotient
In number theory, a nontotient is a positive integer ''n'' which is not a totient number: it is not in the range of Euler's totient function φ, that is, the equation φ(''x'') = ''n'' has no solution ''x''. In other words, ''n'' is a nontotient ...
and also
noncototient In mathematics, a noncototient is a positive integer ''n'' that cannot be expressed as the difference between a positive integer ''m'' and the number of coprime integers below it. That is, ''m'' − φ(''m'') = ''n'', where Ï ...
.
*218 is the number of inequivalent ways to color the 12 edges of a cube using at most 2 colors, where two colorings are equivalent if they differ only by a rotation of the cube.
*There are 218 nondegenerate
Boolean function
In mathematics, a Boolean function is a function whose arguments and result assume values from a two-element set (usually , or ). Alternative names are switching function, used especially in older computer science literature, and truth function ( ...
s of 3 variables.
*The number of surface points on a 7
3 cube.
In other fields
*218 is the current number of votes in the
US House of Representatives
The United States House of Representatives, often referred to as the House of Representatives, the U.S. House, or simply the House, is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together they c ...
a party or coalition needs to win in order to achieve a majority.
*The years
218
Year 218 (Roman numerals, CCXVIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Severus and Adventus (or, less frequently, year ...
and
218 BC
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Year 218 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Scipio and Longus (or, less frequently, year 536 ''Ab urbe condita''). The denomination 218 BC for this year has been ...
*Area code 218, for northern Minnesota.
References
Integers
{{Num-stub