820004 has 12 divisors (see below), whose sum is σ = 1484700. Its totient is φ = 395808.

The previous prime is 819991. The next prime is 820037. The reversal of 820004 is 400028.

It can be written as a sum of positive squares in 2 ways, for example, as 357604 + 462400 = 598^2 + 680^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820004.

It is an unprimeable number.

820004 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3419 + ... + 3650.

It is an arithmetic number, because the mean of its divisors is an integer number (123725).

2⁸²⁰⁰⁰⁴ is an apocalyptic number.

It is an amenable number.

820004 is a deficient number, since it is larger than the sum of its proper divisors (664696).

820004 is a wasteful number, since it uses less digits than its factorization.

820004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7102 (or 7100 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 820004 is about 905.5407224416. The cubic root of 820004 is about 93.5991684247.

The spelling of 820004 in words is "eight hundred twenty thousand, four".