81040632768 has 84 divisors (see below), whose sum is σ = 232381684080. Its totient is φ = 27002689536.

The previous prime is 81040632679. The next prime is 81040632781. The reversal of 81040632768 is 86723604018.

81040632768 is a `hidden beast` number, since 8 + 1 + 0 + 4 + 0 + 632 + 7 + 6 + 8 = 666.

It is a congruent number.

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, 1475821 + ... + 1529747.

It is an arithmetic number, because the mean of its divisors is an integer number (2766448620).

Almost surely, 2^81040632768 is an apocalyptic number.

It is an amenable number.

81040632768 is an abundant number, since it is smaller than the sum of its proper divisors (151341051312).

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

81040632768 is a wasteful number, since it uses less digits than its factorization.

81040632768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56554 (or 56541 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 81040632768 in words is "eighty-one billion, forty million, six hundred thirty-two thousand, seven hundred sixty-eight".