809491 has 2 divisors, whose sum is σ = 809492. Its totient is φ = 809490.

The previous prime is 809461. The next prime is 809507. The reversal of 809491 is 194908.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-809491 is a prime.

It is not a weakly prime, because it can be changed into another prime (809401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404745 + 404746.

It is an arithmetic number, because the mean of its divisors is an integer number (404746).

2⁸⁰⁹⁴⁹¹ is an apocalyptic number.

809491 is a deficient number, since it is larger than the sum of its proper divisors (1).

809491 is an equidigital number, since it uses as much as digits as its factorization.

809491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 809491 is about 899.7171777842. The cubic root of 809491 is about 93.1974453916.

The spelling of 809491 in words is "eight hundred nine thousand, four hundred ninety-one".