290 (number)

This article covers the number 290. For the year, see 290.

← 289 290 291 →
← 200 210 220 230 240 250 260 270 280 290 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred ninety
Ordinal	290th (two hundred ninetieth)
Factorization	2 × 5 × 29
Greek numeral	ΣϞ´
Roman numeral	CCXC, ccxc
Binary	1001000102
Ternary	1012023
Senary	12026
Octal	4428
Duodecimal	20212
Hexadecimal	12216

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.[1]

See also the Bhargava–Hanke 290 theorem.

References

1. "Sloane's A005282 : Mian-Chowla sequence". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.