81372801688 has 32 divisors (see below), whose sum is σ = 153364700160. Its totient is φ = 40475803680.

The previous prime is 81372801673. The next prime is 81372801733. The reversal of 81372801688 is 88610827318.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2680531 + ... + 2710717.

It is an arithmetic number, because the mean of its divisors is an integer number (4792646880).

Almost surely, 2^81372801688 is an apocalyptic number.

It is an amenable number.

81372801688 is a deficient number, since it is larger than the sum of its proper divisors (71991898472).

81372801688 is a wasteful number, since it uses less digits than its factorization.

81372801688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31927 (or 31923 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 52.

The spelling of 81372801688 in words is "eighty-one billion, three hundred seventy-two million, eight hundred one thousand, six hundred eighty-eight".