290 (number)

290 is the natural number after 289 and before 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. 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't be obtained as the sum of any two previous terms in the sequence.

See also Conway's 290 theorem.

In other fields

*"290" is one of Naoki Maeda's pseudonyms.
*"290" was the shipyard number of the "CSS Alabama"

See also the year 290.

291 to 299

*Two hundred [and] ninety-one 291 = 3·97
*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).
*Two hundred [and] ninety-three 293 prime, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, strictly non-palindromic number. For 293 cells in cell biology, see HEK cell.
*Two hundred [and] ninety-four 294 = 2·3·7²
*Two hundred [and] ninety-five 295 = 5·59, also, the numerical designation of seven spur routes of Interstate 95 in the United States.
*Two hundred [and] ninety-six 296 = 2³·37
*Two hundred [and] ninety-seven 297 = 3³·11, decagonal number, Kaprekar number
*Two hundred [and] ninety-eight 298 = 2·149, nontotient, noncototient
*Two hundred [and] ninety-nine 299 = 13·23, highly cototient number, self number, the twelfth cake number