81688801760 has 24 divisors (see below), whose sum is σ = 192989794536. Its totient is φ = 32675520640.

The previous prime is 81688801751. The next prime is 81688801771. The reversal of 81688801760 is 6710888618.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255277346 + ... + 255277665.

It is an arithmetic number, because the mean of its divisors is an integer number (8041241439).

Almost surely, 2^81688801760 is an apocalyptic number.

81688801760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81688801760 is an abundant number, since it is smaller than the sum of its proper divisors (111300992776).

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

81688801760 is a wasteful number, since it uses less digits than its factorization.

81688801760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510555026 (or 510555018 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 53.

The spelling of 81688801760 in words is "eighty-one billion, six hundred eighty-eight million, eight hundred one thousand, seven hundred sixty".