390404 has 24 divisors (see below), whose sum is σ = 795648. Its totient is φ = 164160.

The previous prime is 390391. The next prime is 390407. The reversal of 390404 is 404093.

390404 is nontrivially palindromic in base 3.

It is not an unprimeable number, because it can be changed into a prime (390407) by changing a digit.

390404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1949 + ... + 2139.

It is an arithmetic number, because the mean of its divisors is an integer number (33152).

2³⁹⁰⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

390404 is an abundant number, since it is smaller than the sum of its proper divisors (405244).

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

390404 is a wasteful number, since it uses less digits than its factorization.

390404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 390404 is about 624.8231749863. The cubic root of 390404 is about 73.0866550857.

Adding to 390404 its reverse (404093), we get a palindrome (794497).

Subtracting 390404 from its reverse (404093), we obtain a square (13689 = 117²).

The spelling of 390404 in words is "three hundred ninety thousand, four hundred four".