290 (number)

← 200 210 220 230 240 250 260 270 280 290 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Ordinal	two hundred [and] ninetieth
Cardinal	two hundred [and] ninety
Factorization	$2 \cdot 5 \cdot 29$
Roman numeral	CCXC
Binary	100100010
Hexadecimal	122

290 (two hundred [and] ninety) 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 the Bhargava–Hanke 290 theorem.

In other fields

• "290" was the shipyard number of the CSS Alabama

See also the year 290.

291 to 299

291

Two hundred [and] ninety-one 291 = 3·97

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, 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

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

297

Two hundred [and] ninety-seven 297 = 3³·11, 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