81000865176 has 256 divisors, whose sum is σ = 258095185920. Its totient is φ = 20575296000.

The previous prime is 81000865163. The next prime is 81000865213. The reversal of 81000865176 is 67156800018.

It is a super-2 number, since 2×81000865176² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 16660986 + ... + 16665846.

It is an arithmetic number, because the mean of its divisors is an integer number (1008184320).

Almost surely, 2^81000865176 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 81000865176, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129047592960).

81000865176 is an abundant number, since it is smaller than the sum of its proper divisors (177094320744).

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

81000865176 is a wasteful number, since it uses less digits than its factorization.

81000865176 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5086 (or 5082 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The spelling of 81000865176 in words is "eighty-one billion, eight hundred sixty-five thousand, one hundred seventy-six".