16856511840 has 288 divisors, whose sum is σ = 69608185920. Its totient is φ = 3626237952.

The previous prime is 16856511817. The next prime is 16856511871. The reversal of 16856511840 is 4811565861.

16856511840 is a `hidden beast` number, since 1 + 6 + 8 + 56 + 511 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122176 + ... + 220544.

It is an arithmetic number, because the mean of its divisors is an integer number (241695090).

Almost surely, 2^16856511840 is an apocalyptic number.

16856511840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16856511840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34804092960).

16856511840 is an abundant number, since it is smaller than the sum of its proper divisors (52751674080).

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

16856511840 is a wasteful number, since it uses less digits than its factorization.

16856511840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98414 (or 98403 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 16856511840 in words is "sixteen billion, eight hundred fifty-six million, five hundred eleven thousand, eight hundred forty".