15996636864 has 630 divisors, whose sum is σ = 55849517460. Its totient is φ = 4512568320.

The previous prime is 15996636841. The next prime is 15996636881. The reversal of 15996636864 is 46863669951.

15996636864 is a `hidden beast` number, since 1 + 599 + 6 + 6 + 36 + 8 + 6 + 4 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 516020529 + ... + 516020559.

Almost surely, 2^15996636864 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 15996636864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27924758730).

15996636864 is an abundant number, since it is smaller than the sum of its proper divisors (39852880596).

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

15996636864 is a wasteful number, since it uses less digits than its factorization.

15996636864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 68 counting only the distinct ones).

The product of its digits is 50388480, while the sum is 63.

The spelling of 15996636864 in words is "fifteen billion, nine hundred ninety-six million, six hundred thirty-six thousand, eight hundred sixty-four".