81865608968 has 32 divisors (see below), whose sum is σ = 180333336960. Its totient is φ = 34349206080.

The previous prime is 81865608947. The next prime is 81865608973. The reversal of 81865608968 is 86980656818.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35779280 + ... + 35781567.

It is an arithmetic number, because the mean of its divisors is an integer number (5635416780).

Almost surely, 2^81865608968 is an apocalyptic number.

81865608968 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81865608968 is an abundant number, since it is smaller than the sum of its proper divisors (98467727992).

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

81865608968 is a wasteful number, since it uses less digits than its factorization.

81865608968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71560877 (or 71560873 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 65.

The spelling of 81865608968 in words is "eighty-one billion, eight hundred sixty-five million, six hundred eight thousand, nine hundred sixty-eight".