11515866856 has 96 divisors (see below), whose sum is σ = 24549523200. Its totient is φ = 5055298560.

The previous prime is 11515866833. The next prime is 11515866889. The reversal of 11515866856 is 65866851511.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2470480 + ... + 2475136.

It is an arithmetic number, because the mean of its divisors is an integer number (255724200).

Almost surely, 2^11515866856 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 11515866856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12274761600).

11515866856 is an abundant number, since it is smaller than the sum of its proper divisors (13033656344).

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

11515866856 is a wasteful number, since it uses less digits than its factorization.

11515866856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4779 (or 4762 counting only the distinct ones).

The product of its digits is 1728000, while the sum is 52.

The spelling of 11515866856 in words is "eleven billion, five hundred fifteen million, eight hundred sixty-six thousand, eight hundred fifty-six".