81142117168 has 80 divisors (see below), whose sum is σ = 180345600000. Its totient is φ = 34645072896.

The previous prime is 81142117157. The next prime is 81142117169. The reversal of 81142117168 is 86171124118.

It is a self number, because there is not a number n which added to its sum of digits gives 81142117168.

It is not an unprimeable number, because it can be changed into a prime (81142117169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54130083 + ... + 54131581.

It is an arithmetic number, because the mean of its divisors is an integer number (2254320000).

Almost surely, 2^81142117168 is an apocalyptic number.

It is an amenable number.

81142117168 is an abundant number, since it is smaller than the sum of its proper divisors (99203482832).

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

81142117168 is a wasteful number, since it uses less digits than its factorization.

81142117168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3002 (or 2996 counting only the distinct ones).

The product of its digits is 21504, while the sum is 40.

The spelling of 81142117168 in words is "eighty-one billion, one hundred forty-two million, one hundred seventeen thousand, one hundred sixty-eight".