115517775721 has 4 divisors (see below), whose sum is σ = 115520143744. Its totient is φ = 115515407700.

The previous prime is 115517775719. The next prime is 115517775757. The reversal of 115517775721 is 127577715511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 115517775721 - 2¹ = 115517775719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115517775421) 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, 1109265 + ... + 1208926.

It is an arithmetic number, because the mean of its divisors is an integer number (28880035936).

Almost surely, 2^115517775721 is an apocalyptic number.

It is an amenable number.

115517775721 is a deficient number, since it is larger than the sum of its proper divisors (2368023).

115517775721 is an equidigital number, since it uses as much as digits as its factorization.

115517775721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2368022.

The product of its digits is 600250, while the sum is 49.

The spelling of 115517775721 in words is "one hundred fifteen billion, five hundred seventeen million, seven hundred seventy-five thousand, seven hundred twenty-one".