16399781728 has 96 divisors (see below), whose sum is σ = 36254161440. Its totient is φ = 7236956160.

The previous prime is 16399781693. The next prime is 16399781743. The reversal of 16399781728 is 82718799361.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7409550 + ... + 7411762.

It is an arithmetic number, because the mean of its divisors is an integer number (377647515).

Almost surely, 2^16399781728 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 16399781728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18127080720).

16399781728 is an abundant number, since it is smaller than the sum of its proper divisors (19854379712).

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

16399781728 is a wasteful number, since it uses less digits than its factorization.

16399781728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2840 (or 2832 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 61.

The spelling of 16399781728 in words is "sixteen billion, three hundred ninety-nine million, seven hundred eighty-one thousand, seven hundred twenty-eight".