805891 has 2 divisors, whose sum is σ = 805892. Its totient is φ = 805890.

The previous prime is 805877. The next prime is 805901. The reversal of 805891 is 198508.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 805891 - 2⁵ = 805859 is a prime.

It is not a weakly prime, because it can be changed into another prime (805811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402945 + 402946.

It is an arithmetic number, because the mean of its divisors is an integer number (402946).

2⁸⁰⁵⁸⁹¹ is an apocalyptic number.

805891 is a deficient number, since it is larger than the sum of its proper divisors (1).

805891 is an equidigital number, since it uses as much as digits as its factorization.

805891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 805891 is about 897.7143198145. The cubic root of 805891 is about 93.0590829715.

The spelling of 805891 in words is "eight hundred five thousand, eight hundred ninety-one".