404405820 has 216 divisors, whose sum is σ = 1537177824. Its totient is φ = 85300992.

The previous prime is 404405791. The next prime is 404405821. The reversal of 404405820 is 28504404.

404405820 is a `hidden beast` number, since 40 + 4 + 40 + 582 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404405821) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 112897 + ... + 116423.

It is an arithmetic number, because the mean of its divisors is an integer number (7116564).

Almost surely, 2^404405820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 404405820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (768588912).

404405820 is an abundant number, since it is smaller than the sum of its proper divisors (1132772004).

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

404405820 is a wasteful number, since it uses less digits than its factorization.

404405820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3569 (or 3557 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

The square root of 404405820 is about 20109.8438581706. The cubic root of 404405820 is about 739.5016244974.

The spelling of 404405820 in words is "four hundred four million, four hundred five thousand, eight hundred twenty".