290 (number)

290 (two hundred [and] ninety) is the natural number following 289 and preceding 291.

← 289 290 291 →
Cardinaltwo hundred ninety
(two hundred ninetieth)
Factorization2 × 5 × 29
Greek numeralΣϞ´
Roman numeralCCXC

In mathematicsEdit

The product of three primes, 290 is a sphenic number, 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 and a noncototient, it is also an untouchable number.

290 is the 16th member of the Mian–Chowla sequence; it can not be obtained as the sum of any two previous terms in the sequence.[1]

See also the Bhargava–Hanke 290 theorem.

In other fieldsEdit

See also the year 290.

Integers from 291 to 299Edit


291 = 3·97, a semiprime, floor(3^14/2^14) (sequence A002379 in the OEIS).


292 = 22·73, noncototient, untouchable number. The continued fraction representation of   is [3; 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  , repdigit in base 8 (444).


293 is prime, Sophie Germain prime, Chen prime, Irregular prime, Eisenstein prime with no imaginary part, strictly non-palindromic number. For 293 cells in cell biology, see HEK cell.


294 = 2·3·72, number of rooted trees with 28 vertices in which vertices at the same level have the same degree (sequence A003238 in the OEIS).


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


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 squares (illustration) (sequence A331452 in the OEIS), number of surface points on a 83 cube.[2]


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


298 = 2·149, nontotient, noncototient, number of polynomial symmetric functions of matrix of order 6 under separate row and column permutations[3]


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


  1. ^ "Sloane's A005282 : Mian-Chowla sequence". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  2. ^ Sloane, N. J. A. (ed.). "Sequence A005897". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  3. ^ Sloane, N. J. A. (ed.). "Sequence A007716 (Number of polynomial symmetric functions of matrix of order n under separate row and column permutations)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.