81659760912 has 60 divisors (see below), whose sum is σ = 229130763264. Its totient is φ = 27148831680.

The previous prime is 81659760893. The next prime is 81659760953. The reversal of 81659760912 is 21906795618.

81659760912 is a `hidden beast` number, since 8 + 16 + 5 + 9 + 7 + 609 + 12 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 685164 + ... + 795467.

Almost surely, 2^81659760912 is an apocalyptic number.

It is an amenable number.

81659760912 is an abundant number, since it is smaller than the sum of its proper divisors (147471002352).

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

81659760912 is a wasteful number, since it uses less digits than its factorization.

81659760912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481028 (or 1481019 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 81659760912 in words is "eighty-one billion, six hundred fifty-nine million, seven hundred sixty thousand, nine hundred twelve".