81117155171118 has 24 divisors (see below), whose sum is σ = 178323663435624. Its totient is φ = 24580956112240.

The previous prime is 81117155171083. The next prime is 81117155171123.

81117155171118 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81117155171118² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 55865808621 + ... + 55865810072.

It is an arithmetic number, because the mean of its divisors is an integer number (7430152643151).

Almost surely, 2^{81117155171118} is an apocalyptic number.

81117155171118 is an abundant number, since it is smaller than the sum of its proper divisors (97206508264506).

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

81117155171118 is a wasteful number, since it uses less digits than its factorization.

81117155171118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111731618720 (or 111731618709 counting only the distinct ones).

The product of its digits is 78400, while the sum is 48.

The spelling of 81117155171118 in words is "eighty-one trillion, one hundred seventeen billion, one hundred fifty-five million, one hundred seventy-one thousand, one hundred eighteen".