15965856816 has 320 divisors, whose sum is σ = 54204530688. Its totient is φ = 3929554944.

The previous prime is 15965856773. The next prime is 15965856821. The reversal of 15965856816 is 61865856951.

15965856816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 15965856816.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9429666 + ... + 9431358.

Almost surely, 2^15965856816 is an apocalyptic number.

15965856816 is a gapful number since it is divisible by the number (16) 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 15965856816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27102265344).

15965856816 is an abundant number, since it is smaller than the sum of its proper divisors (38238673872).

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

15965856816 is a wasteful number, since it uses less digits than its factorization.

15965856816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1868 (or 1862 counting only the distinct ones).

The product of its digits is 15552000, while the sum is 60.

The spelling of 15965856816 in words is "fifteen billion, nine hundred sixty-five million, eight hundred fifty-six thousand, eight hundred sixteen".