16405398990 has 384 divisors, whose sum is σ = 48910417920. Its totient is φ = 3940005888.

The previous prime is 16405398983. The next prime is 16405399027. The reversal of 16405398990 is 9989350461.

16405398990 is a `hidden beast` number, since 16 + 4 + 0 + 539 + 8 + 9 + 90 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 129176307 + ... + 129176433.

It is an arithmetic number, because the mean of its divisors is an integer number (127370880).

Almost surely, 2^16405398990 is an apocalyptic number.

16405398990 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 16405398990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24455208960).

16405398990 is an abundant number, since it is smaller than the sum of its proper divisors (32505018930).

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

16405398990 is a wasteful number, since it uses less digits than its factorization.

16405398990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 266 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 16405398990 in words is "sixteen billion, four hundred five million, three hundred ninety-eight thousand, nine hundred ninety".