404638 has 16 divisors (see below), whose sum is σ = 665280. Its totient is φ = 183456.

The previous prime is 404597. The next prime is 404671. The reversal of 404638 is 836404.

404638 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×404638² = 327463822088, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

404638 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, 1956 + ... + 2152.

It is an arithmetic number, because the mean of its divisors is an integer number (41580).

2⁴⁰⁴⁶³⁸ is an apocalyptic number.

404638 is a deficient number, since it is larger than the sum of its proper divisors (260642).

404638 is a wasteful number, since it uses less digits than its factorization.

404638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 404638 is about 636.1116254243. Note that the first 3 decimals coincide. The cubic root of 404638 is about 73.9643119856.

It can be divided in two parts, 404 and 638, that multiplied together give a palindrome (257752).

The spelling of 404638 in words is "four hundred four thousand, six hundred thirty-eight".