181397856911 has 4 divisors (see below), whose sum is σ = 182156844000. Its totient is φ = 180638869824.

The previous prime is 181397856881. The next prime is 181397856919. The reversal of 181397856911 is 119658793181.

181397856911 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 119658793181 = 83 ⋅1441672207.

It is a cyclic number.

It is not a de Polignac number, because 181397856911 - 2⁶ = 181397856847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181397856919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 379493186 + ... + 379493663.

It is an arithmetic number, because the mean of its divisors is an integer number (45539211000).

Almost surely, 2^181397856911 is an apocalyptic number.

181397856911 is a deficient number, since it is larger than the sum of its proper divisors (758987089).

181397856911 is an equidigital number, since it uses as much as digits as its factorization.

181397856911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758987088.

The product of its digits is 3265920, while the sum is 59.

The spelling of 181397856911 in words is "one hundred eighty-one billion, three hundred ninety-seven million, eight hundred fifty-six thousand, nine hundred eleven".