805819 has 4 divisors (see below), whose sum is σ = 920944. Its totient is φ = 690696.

The previous prime is 805811. The next prime is 805843. The reversal of 805819 is 918508.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 805819 - 2³ = 805811 is a prime.

It is a super-2 number, since 2×805819² = 1298688521522, which contains 22 as substring.

It is a Duffinian number.

805819 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (805811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57552 + ... + 57565.

It is an arithmetic number, because the mean of its divisors is an integer number (230236).

2⁸⁰⁵⁸¹⁹ is an apocalyptic number.

805819 is a deficient number, since it is larger than the sum of its proper divisors (115125).

805819 is a wasteful number, since it uses less digits than its factorization.

805819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115124.

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

The square root of 805819 is about 897.6742170743. The cubic root of 805819 is about 93.0563115241.

The spelling of 805819 in words is "eight hundred five thousand, eight hundred nineteen".