115566646721 has 4 divisors (see below), whose sum is σ = 115608086100. Its totient is φ = 115525207344.

The previous prime is 115566646673. The next prime is 115566646759. The reversal of 115566646721 is 127646665511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76189800625 + 39376846096 = 276025^2 + 198436^2 .

It is a cyclic number.

It is not a de Polignac number, because 115566646721 - 2¹⁴ = 115566630337 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 115566646721.

It is not an unprimeable number, because it can be changed into a prime (115566646781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20715506 + ... + 20721083.

It is an arithmetic number, because the mean of its divisors is an integer number (28902021525).

Almost surely, 2^115566646721 is an apocalyptic number.

It is an amenable number.

115566646721 is a deficient number, since it is larger than the sum of its proper divisors (41439379).

115566646721 is an equidigital number, since it uses as much as digits as its factorization.

115566646721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41439378.

The product of its digits is 1814400, while the sum is 50.

The spelling of 115566646721 in words is "one hundred fifteen billion, five hundred sixty-six million, six hundred forty-six thousand, seven hundred twenty-one".