290861 has 2 divisors, whose sum is σ = 290862. Its totient is φ = 290860.

The previous prime is 290839. The next prime is 290869. The reversal of 290861 is 168092.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164836 + 126025 = 406^2 + 355^2 .

It is a cyclic number.

It is not a de Polignac number, because 290861 - 2¹⁰ = 289837 is a prime.

It is a Chen prime.

It is equal to p₂₅₂₉₈ and since 290861 and 25298 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 290861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (290869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145430 + 145431.

It is an arithmetic number, because the mean of its divisors is an integer number (145431).

2²⁹⁰⁸⁶¹ is an apocalyptic number.

It is an amenable number.

290861 is a deficient number, since it is larger than the sum of its proper divisors (1).

290861 is an equidigital number, since it uses as much as digits as its factorization.

290861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 290861 is about 539.3153066621. The cubic root of 290861 is about 66.2565010827.

The spelling of 290861 in words is "two hundred ninety thousand, eight hundred sixty-one".