81688192104440 has 128 divisors (see below), whose sum is σ = 199565971292160. Its totient is φ = 30012457373184.

The previous prime is 81688192104437. The next prime is 81688192104559. The reversal of 81688192104440 is 4440129188618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15530744 + ... + 20114183.

It is an arithmetic number, because the mean of its divisors is an integer number (1559109150720).

Almost surely, 2^{81688192104440} is an apocalyptic number.

It is an amenable number.

81688192104440 is an abundant number, since it is smaller than the sum of its proper divisors (117877779187720).

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

81688192104440 is a wasteful number, since it uses less digits than its factorization.

81688192104440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35645061 (or 35645057 counting only the distinct ones).

The product of its (nonzero) digits is 3538944, while the sum is 56.

The spelling of 81688192104440 in words is "eighty-one trillion, six hundred eighty-eight billion, one hundred ninety-two million, one hundred four thousand, four hundred forty".