16404990 has 64 divisors (see below), whose sum is σ = 45342720. Its totient is φ = 3720960.

The previous prime is 16404989. The next prime is 16405007. The reversal of 16404990 is 9940461.

It is a zygodrome in base 9.

It is a congruent number.

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, 39906 + ... + 40314.

It is an arithmetic number, because the mean of its divisors is an integer number (708480).

Almost surely, 2^16404990 is an apocalyptic number.

16404990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 16404990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22671360).

16404990 is an abundant number, since it is smaller than the sum of its proper divisors (28937730).

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

16404990 is a wasteful number, since it uses less digits than its factorization.

16404990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 16404990 is about 4050.3073957417. The cubic root of 16404990 is about 254.0925841005.

The spelling of 16404990 in words is "sixteen million, four hundred four thousand, nine hundred ninety".