290 (two hundred [and] ninety) is the natural number following 289 and preceding 291. In mathematics 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. See also the Bhargava–Hanke 290 theorem. In other fields "290" was the shipyard number of the CSS Alabama See also the year 290. Integers from 291 to 299 291 291 = 3·97, a semiprime, floor(3^14/2^14) . 292 292 = 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). 293 293 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. 294 294 = 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. 296 296 = 23·37, refactorable number, 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) , number of surface points on a 83 cube. 297 297 = 33·11, number of integer partitions of 17, decagonal number, Kaprekar number 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 References Integers