819904 has 28 divisors (see below), whose sum is σ = 1700784. Its totient is φ = 391424.

The previous prime is 819899. The next prime is 819911. The reversal of 819904 is 409918.

819904 = T₁₂₇ + T₁₂₈ + ... + T₁₉₀.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1194 + ... + 1750.

2⁸¹⁹⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 819904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850392).

819904 is an abundant number, since it is smaller than the sum of its proper divisors (880880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

819904 is a wasteful number, since it uses less digits than its factorization.

819904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 819904 is about 905.4855051297. The cubic root of 819904 is about 93.5953634443.

The spelling of 819904 in words is "eight hundred nineteen thousand, nine hundred four".