290 (two hundred ndninety) 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 ...

following 289 and preceding

291 __NOTOC__ Year 291 ( CCXCI) 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 Tiberianus and Dio (or, less frequently, year 1044 ''A ...

In mathematics

The product of three primes, 290 is a

sphenic number In number theory, a sphenic number (from grc, σφήνα, 'wedge') is a positive integer that is the product of three distinct prime numbers. Because there are infinitely many prime numbers, there are also infinitely many sphenic numbers. Definit ...

, and the sum of four consecutive primes (67 + 71 + 73 + 79). The sum of the squares of the divisors of 17 is 290. Not only is it a

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 nontotien ...

and a

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 � ...

, it is also an

untouchable number An untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer (including the untouchable number itself). That is, these numbers are not in the image of the aliquot sum function. ...

. 290 is the 16th member of the

Mian–Chowla sequence In mathematics, the Mian–Chowla sequence is an integer sequence defined recursively in the following way. The sequence starts with :a_1 = 1. Then for n>1, a_n is the smallest integer such that every pairwise sum :a_i + a_j is distinct, for ...

; it can not be obtained as the sum of any two previous terms in the sequence. See also the Bhargava–Hanke 290 theorem.

In other fields

*"290" was the shipyard number of the ''

CSS Alabama CSS ''Alabama'' was a screw sloop-of-war built in 1862 for the Confederate States Navy at Birkenhead on the River Mersey opposite Liverpool, England by John Laird Sons and Company. ''Alabama'' served as a successful commerce raider, attackin ...

'' See also the year

290 __NOTOC__ Year 290 ( CCXC) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Valerius and Valerius (or, less frequently, yea ...

Integers from 291 to 299

291

291 = 3·97, a

semiprime In mathematics, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other, so the semiprimes include the squares of prime numbers. Because there are infinitely many prime ...

, floor(3^14/2^14) .

292

292 = 2²·73, noncototient, untouchable number. The

continued fraction In mathematics, a continued fraction is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number, then writing this other number as the sum of its integer ...

representation of

\pi

is ; 7, 15, 1, 292, 1, 1, 1, 2... the convergent obtained by truncating before the surprisingly large term 292 yields the excellent rational approximation 355/113 to

\pi

repdigit In recreational mathematics, a repdigit or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system (often implicitly decimal). The word is a portmanteau of repeated and digit. Example ...

in base 8 (444).

293

293 is prime,

Sophie Germain prime In number theory, a prime number ''p'' is a if 2''p'' + 1 is also prime. The number 2''p'' + 1 associated with a Sophie Germain prime is called a . For example, 11 is a Sophie Germain prime and 2 × 11 + ...

Chen prime A prime number ''p'' is called a Chen prime if ''p'' + 2 is either a prime or a product of two primes (also called a semiprime). The even number 2''p'' + 2 therefore satisfies Chen's theorem. The Chen primes are named after Chen Jingru ...

Irregular prime In number theory, a regular prime is a special kind of prime number, defined by Ernst Kummer in 1850 to prove certain cases of Fermat's Last Theorem. Regular primes may be defined via the divisibility of either class numbers or of Bernoulli num ...

Eisenstein prime In mathematics, an Eisenstein prime is an Eisenstein integer : z = a + b\,\omega, \quad \text \quad \omega = e^, that is irreducible (or equivalently prime) in the ring-theoretic sense: its only Eisenstein divisors are the units , itself ...

with no imaginary part, strictly non-palindromic number. For 293 cells in cell biology, see

HEK cell Human embryonic kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, or less precisely as HEK cells, are a specific immortalised cell line derived from a spontaneously miscarried or aborted fetus or human embryonic kidney cells ...

294

294 = 2·3·7², number of rooted trees with 28 vertices in which vertices at the same level have the same degree .

295

295 = 5·59, centered tetrahedral number, also the numerical designation of seven circumferential or half-circumferential routes of Interstate 95 in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

296

296 = 2³·37, unique period in base 2, number of regions formed by drawing the line segments connecting any two of the 12 perimeter points of an 2 times 4 grid of square
(illustration)
, number of surface points on a 8³ cube.

297

297 = 3³·11, number of integer partitions of 17,

decagonal number A decagonal number is a figurate number that extends the concept of triangular and square numbers to the decagon (a ten-sided polygon). However, unlike the triangular and square numbers, the patterns involved in the construction of decagonal number ...

Kaprekar number In mathematics, a natural number in a given number base is a p-Kaprekar number if the representation of its square in that base can be split into two parts, where the second part has p digits, that add up to the original number. The numbers are n ...

298

298 = 2·149, nontotient, noncototient, number of polynomial symmetric functions of matrix of order 6 under separate row and column permutations

299

299 = 13·23, highly cototient number, self number, the twelfth

cake number In mathematics, the cake number, denoted by ''Cn'', is the maximum of the number of regions into which a 3-dimensional cube can be partitioned by exactly ''n'' planes. The cake number is so-called because one may imagine each partition of the cu ...

References

{{DEFAULTSORT:290 (Number) Integers