804639 has 16 divisors (see below), whose sum is σ = 1203840. Its totient is φ = 473760.

The previous prime is 804619. The next prime is 804653. The reversal of 804639 is 936408.

It is not a de Polignac number, because 804639 - 2⁵ = 804607 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (804619) 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, 892 + ... + 1550.

It is an arithmetic number, because the mean of its divisors is an integer number (75240).

2⁸⁰⁴⁶³⁹ is an apocalyptic number.

804639 is a deficient number, since it is larger than the sum of its proper divisors (399201).

804639 is a wasteful number, since it uses less digits than its factorization.

804639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 804639 is about 897.0167222522. The cubic root of 804639 is about 93.0108670386.

Subtracting from 804639 its sum of digits (30), we obtain a square (804609 = 897²).

Subtracting 804639 from its reverse (936408), we obtain a square (131769 = 363²).

The spelling of 804639 in words is "eight hundred four thousand, six hundred thirty-nine".