81338897764973 has 16 divisors (see below), whose sum is σ = 83039040552960. Its totient is φ = 79649977292016.

The previous prime is 81338897764921. The next prime is 81338897765029. The reversal of 81338897764973 is 37946779883318.

It is a cyclic number.

It is not a de Polignac number, because 81338897764973 - 2³⁰ = 81337824023149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81338897764891 and 81338897764900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81338897763973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16510136 + ... + 20862942.

It is an arithmetic number, because the mean of its divisors is an integer number (5189940034560).

Almost surely, 2^{81338897764973} is an apocalyptic number.

It is an amenable number.

81338897764973 is a deficient number, since it is larger than the sum of its proper divisors (1700142787987).

81338897764973 is a wasteful number, since it uses less digits than its factorization.

81338897764973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4354096.

The product of its digits is 9217732608, while the sum is 83.

The spelling of 81338897764973 in words is "eighty-one trillion, three hundred thirty-eight billion, eight hundred ninety-seven million, seven hundred sixty-four thousand, nine hundred seventy-three".