805811 has 2 divisors, whose sum is σ = 805812. Its totient is φ = 805810.

The previous prime is 805807. The next prime is 805843. The reversal of 805811 is 118508.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 805811 - 2² = 805807 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (805891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402905 + 402906.

It is an arithmetic number, because the mean of its divisors is an integer number (402906).

2⁸⁰⁵⁸¹¹ is an apocalyptic number.

805811 is a deficient number, since it is larger than the sum of its proper divisors (1).

805811 is an equidigital number, since it uses as much as digits as its factorization.

805811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 23.

The square root of 805811 is about 897.6697611037. The cubic root of 805811 is about 93.0560035753.

The spelling of 805811 in words is "eight hundred five thousand, eight hundred eleven".