404121906 has 64 divisors (see below), whose sum is σ = 949132800. Its totient is φ = 127102608.

The previous prime is 404121863. The next prime is 404121917. The reversal of 404121906 is 609121404.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 404121906.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 314341 + ... + 315623.

It is an arithmetic number, because the mean of its divisors is an integer number (14830200).

Almost surely, 2^404121906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 404121906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (474566400).

404121906 is an abundant number, since it is smaller than the sum of its proper divisors (545010894).

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

404121906 is a wasteful number, since it uses less digits than its factorization.

404121906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620 (or 1614 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 404121906 is about 20102.7835386048. The cubic root of 404121906 is about 739.3285277333.

The spelling of 404121906 in words is "four hundred four million, one hundred twenty-one thousand, nine hundred six".