290991 has 4 divisors (see below), whose sum is σ = 387992. Its totient is φ = 193992.

The previous prime is 290987. The next prime is 290993. The reversal of 290991 is 199092.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 290991 - 2² = 290987 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (290993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48496 + ... + 48501.

It is an arithmetic number, because the mean of its divisors is an integer number (96998).

2²⁹⁰⁹⁹¹ is an apocalyptic number.

290991 is a deficient number, since it is larger than the sum of its proper divisors (97001).

290991 is an equidigital number, since it uses as much as digits as its factorization.

290991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97000.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 290991 is about 539.4358163860. The cubic root of 290991 is about 66.2663707022.

The spelling of 290991 in words is "two hundred ninety thousand, nine hundred ninety-one".