81372838833 has 48 divisors (see below), whose sum is σ = 138123183744. Its totient is φ = 45511418880.

The previous prime is 81372838823. The next prime is 81372838837. The reversal of 81372838833 is 33883827318.

It is not a de Polignac number, because 81372838833 - 2⁵ = 81372838801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81372838833.

It is not an unprimeable number, because it can be changed into a prime (81372838837) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7862260 + ... + 7872602.

It is an arithmetic number, because the mean of its divisors is an integer number (2877566328).

Almost surely, 2^81372838833 is an apocalyptic number.

It is an amenable number.

81372838833 is a deficient number, since it is larger than the sum of its proper divisors (56750344911).

81372838833 is a wasteful number, since it uses less digits than its factorization.

81372838833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16486 (or 16483 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The spelling of 81372838833 in words is "eighty-one billion, three hundred seventy-two million, eight hundred thirty-eight thousand, eight hundred thirty-three".