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.
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