290 (number)

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. If you multiply 5, 2, and 29, you get 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

See also the year 290.

291

Two hundred [and] ninety-one 291 = 3·97, a semiprime.

292

Two hundred [and] ninety-two 292 = 2²·73, noncototient, untouchable number. The continued fraction representation of pi 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 pi, repdigit in base 8 (444).

293

Two hundred [and] ninety-three 293 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

Two hundred [and] ninety-four 294 = 2·3·7², unique period in base 10

295

Two hundred [and] ninety-five 295 = 5·59, also, the numerical designation of seven circumfrental or half-circumfrental routes of Interstate 95 in the United States.

296

Two hundred [and] ninety-six 296 = 2³·37, unique period in base 2

297

Two hundred [and] ninety-seven 297 = 3³·11, number of integer partitions of 17, decagonal number, Kaprekar number

298

Two hundred [and] ninety-eight 298 = 2·149, nontotient, noncototient

299

Two hundred [and] ninety-nine 299 = 13·23, highly cototient number, self number, the twelfth cake number