400404 has 24 divisors (see below), whose sum is σ = 951328. Its totient is φ = 131040.

The previous prime is 400391. The next prime is 400409. The reversal of 400404 is 404004.

It is a Harshad number since it is a multiple of its sum of digits (12).

400404 is a modest number, since divided by 404 gives 40 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 400404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400409) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 459 + ... + 1005.

2⁴⁰⁰⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

400404 is an abundant number, since it is smaller than the sum of its proper divisors (550924).

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

400404 is a wasteful number, since it uses less digits than its factorization.

400404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615 (or 613 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 12.

The square root of 400404 is about 632.7748414721. The cubic root of 400404 is about 73.7054274383.

Adding to 400404 its reverse (404004), we get a palindrome (804408).

Subtracting 400404 from its reverse (404004), we obtain a square (3600 = 60²).

The spelling of 400404 in words is "four hundred thousand, four hundred four", and thus it is an iban number.