805439 has 4 divisors (see below), whose sum is σ = 822624. Its totient is φ = 788256.

The previous prime is 805421. The next prime is 805451. The reversal of 805439 is 934508.

805439 = 42² + 43² + ... + 135².

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-805439 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 805439.

It is not an unprimeable number, because it can be changed into a prime (805499) 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 3 ways as a sum of consecutive naturals, for example, 8522 + ... + 8615.

It is an arithmetic number, because the mean of its divisors is an integer number (205656).

2⁸⁰⁵⁴³⁹ is an apocalyptic number.

805439 is a deficient number, since it is larger than the sum of its proper divisors (17185).

805439 is a wasteful number, since it uses less digits than its factorization.

805439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17184.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 805439 is about 897.4625340369. The cubic root of 805439 is about 93.0416817051.

The spelling of 805439 in words is "eight hundred five thousand, four hundred thirty-nine".