81168442192 has 80 divisors (see below), whose sum is σ = 166018874112. Its totient is φ = 38368788480.

The previous prime is 81168442177. The next prime is 81168442211. The reversal of 81168442192 is 29124486118.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11119888 + ... + 11127184.

Almost surely, 2^81168442192 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81168442192, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83009437056).

81168442192 is an abundant number, since it is smaller than the sum of its proper divisors (84850431920).

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

81168442192 is a wasteful number, since it uses less digits than its factorization.

81168442192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7676 (or 7670 counting only the distinct ones).

The product of its digits is 221184, while the sum is 46.

The spelling of 81168442192 in words is "eighty-one billion, one hundred sixty-eight million, four hundred forty-two thousand, one hundred ninety-two".