81558911192 has 32 divisors (see below), whose sum is σ = 172577638800. Its totient is φ = 35793878400.

The previous prime is 81558911183. The next prime is 81558911243. The reversal of 81558911192 is 29111985518.

It is a self number, because there is not a number n which added to its sum of digits gives 81558911192.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15976859 + ... + 15981962.

Almost surely, 2^81558911192 is an apocalyptic number.

It is an amenable number.

81558911192 is an abundant number, since it is smaller than the sum of its proper divisors (91018727608).

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

81558911192 is a wasteful number, since it uses less digits than its factorization.

81558911192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31958867 (or 31958863 counting only the distinct ones).

The product of its digits is 259200, while the sum is 50.

The spelling of 81558911192 in words is "eighty-one billion, five hundred fifty-eight million, nine hundred eleven thousand, one hundred ninety-two".