115805906781 has 4 divisors (see below), whose sum is σ = 154407875712. Its totient is φ = 77203937852.

The previous prime is 115805906773. The next prime is 115805906807. The reversal of 115805906781 is 187609508511.

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 115805906781 - 2³ = 115805906773 is a prime.

It is a super-2 number, since 2×115805906781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115805906731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19300984461 + ... + 19300984466.

It is an arithmetic number, because the mean of its divisors is an integer number (38601968928).

Almost surely, 2^115805906781 is an apocalyptic number.

It is an amenable number.

115805906781 is a deficient number, since it is larger than the sum of its proper divisors (38601968931).

115805906781 is an equidigital number, since it uses as much as digits as its factorization.

115805906781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38601968930.

The product of its (nonzero) digits is 604800, while the sum is 51.

The spelling of 115805906781 in words is "one hundred fifteen billion, eight hundred five million, nine hundred six thousand, seven hundred eighty-one".