81002166868 has 12 divisors (see below), whose sum is σ = 162004333792. Its totient is φ = 34715214360.

The previous prime is 81002166857. The next prime is 81002166871. The reversal of 81002166868 is 86866120018.

81002166868 is an admirable number.

It is a super-2 number, since 2×81002166868² (a number of 23 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 (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1446467238 + ... + 1446467293.

Almost surely, 2^81002166868 is an apocalyptic number.

It is an amenable number.

81002166868 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81002166868 is a wasteful number, since it uses less digits than its factorization.

81002166868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2892934542 (or 2892934540 counting only the distinct ones).

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

The spelling of 81002166868 in words is "eighty-one billion, two million, one hundred sixty-six thousand, eight hundred sixty-eight".