81497475768 has 16 divisors (see below), whose sum is σ = 203743689480. Its totient is φ = 27165825248.

The previous prime is 81497475733. The next prime is 81497475821. The reversal of 81497475768 is 86757479418.

It is a junction number, because it is equal to n+sod(n) for n = 81497475699 and 81497475708.

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, 1697864055 + ... + 1697864102.

Almost surely, 2^81497475768 is an apocalyptic number.

It is an amenable number.

81497475768 is an abundant number, since it is smaller than the sum of its proper divisors (122246213712).

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

81497475768 is a wasteful number, since it uses less digits than its factorization.

81497475768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3395728166 (or 3395728162 counting only the distinct ones).

The product of its digits is 94832640, while the sum is 66.

The spelling of 81497475768 in words is "eighty-one billion, four hundred ninety-seven million, four hundred seventy-five thousand, seven hundred sixty-eight".