890809 has 2 divisors, whose sum is σ = 890810. Its totient is φ = 890808.

The previous prime is 890803. The next prime is 890821. The reversal of 890809 is 908098.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 783225 + 107584 = 885^2 + 328^2 .

It is a cyclic number.

It is not a de Polignac number, because 890809 - 2¹¹ = 888761 is a prime.

It is not a weakly prime, because it can be changed into another prime (890803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445404 + 445405.

It is an arithmetic number, because the mean of its divisors is an integer number (445405).

2⁸⁹⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

890809 is a deficient number, since it is larger than the sum of its proper divisors (1).

890809 is an equidigital number, since it uses as much as digits as its factorization.

890809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 890809 is about 943.8267849558. The cubic root of 890809 is about 96.2191535493.

The spelling of 890809 in words is "eight hundred ninety thousand, eight hundred nine".