404404021 has 8 divisors (see below), whose sum is σ = 477085184. Its totient is φ = 335450160.

The previous prime is 404404003. The next prime is 404404031. The reversal of 404404021 is 120404404.

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

It is a cyclic number.

It is not a de Polignac number, because 404404021 - 2⁹ = 404403509 is a prime.

It is a super-2 number, since 2×404404021² = 327085224401936882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 404404021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404404031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 931590 + ... + 932023.

It is an arithmetic number, because the mean of its divisors is an integer number (59635648).

Almost surely, 2^404404021 is an apocalyptic number.

It is an amenable number.

404404021 is a deficient number, since it is larger than the sum of its proper divisors (72681163).

404404021 is a wasteful number, since it uses less digits than its factorization.

404404021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863651.

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 404404021 is about 20109.7991287830. The cubic root of 404404021 is about 739.5005279377.

Adding to 404404021 its reverse (120404404), we get a palindrome (524808425).

The spelling of 404404021 in words is "four hundred four million, four hundred four thousand, twenty-one".