404391 has 8 divisors (see below), whose sum is σ = 580720. Its totient is φ = 248832.

The previous prime is 404389. The next prime is 404399. The reversal of 404391 is 193404.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 404391 - 2¹ = 404389 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5146 + ... + 5223.

It is an arithmetic number, because the mean of its divisors is an integer number (72590).

2⁴⁰⁴³⁹¹ is an apocalyptic number.

404391 is a deficient number, since it is larger than the sum of its proper divisors (176329).

404391 is a wasteful number, since it uses less digits than its factorization.

404391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10385.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 404391 is about 635.9174474725. The cubic root of 404391 is about 73.9492591040.

Adding to 404391 its reverse (193404), we get a palindrome (597795).

The spelling of 404391 in words is "four hundred four thousand, three hundred ninety-one".