805845 has 16 divisors (see below), whose sum is σ = 1331712. Its totient is φ = 415680.

The previous prime is 805843. The next prime is 805853. The reversal of 805845 is 548508.

It is not a de Polignac number, because 805845 - 2¹ = 805843 is a prime.

It is a Curzon number.

805845 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805843) 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 in 15 ways as a sum of consecutive naturals, for example, 402 + ... + 1331.

It is an arithmetic number, because the mean of its divisors is an integer number (83232).

2⁸⁰⁵⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

805845 is a deficient number, since it is larger than the sum of its proper divisors (525867).

805845 is a wasteful number, since it uses less digits than its factorization.

805845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1772.

The product of its (nonzero) digits is 6400, while the sum is 30.

The square root of 805845 is about 897.6886988260. The cubic root of 805845 is about 93.0573123436.

Subtracting from 805845 its sum of digits (30), we obtain a triangular number (805815 = T₁₂₆₉).

The spelling of 805845 in words is "eight hundred five thousand, eight hundred forty-five".