404389640 has 32 divisors (see below), whose sum is σ = 914976000. Its totient is φ = 160849344.

The previous prime is 404389633. The next prime is 404389663. The reversal of 404389640 is 46983404.

It is a junction number, because it is equal to n+sod(n) for n = 404389594 and 404389603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21080 + ... + 35399.

It is an arithmetic number, because the mean of its divisors is an integer number (28593000).

Almost surely, 2^404389640 is an apocalyptic number.

404389640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

404389640 is an abundant number, since it is smaller than the sum of its proper divisors (510586360).

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

404389640 is a wasteful number, since it uses less digits than its factorization.

404389640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56669 (or 56665 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 38.

The square root of 404389640 is about 20109.4415636039. The cubic root of 404389640 is about 739.4917620479.

The spelling of 404389640 in words is "four hundred four million, three hundred eighty-nine thousand, six hundred forty".