81065688057 has 16 divisors (see below), whose sum is σ = 120101760000. Its totient is φ = 54041792112.

The previous prime is 81065688019. The next prime is 81065688131. The reversal of 81065688057 is 75088656018.

It is not a de Polignac number, because 81065688057 - 2¹⁹ = 81065163769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81065687994 and 81065688012.

It is not an unprimeable number, because it can be changed into a prime (81065688257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1220419 + ... + 1285127.

It is an arithmetic number, because the mean of its divisors is an integer number (7506360000).

Almost surely, 2^81065688057 is an apocalyptic number.

It is an amenable number.

81065688057 is a deficient number, since it is larger than the sum of its proper divisors (39036071943).

81065688057 is a wasteful number, since it uses less digits than its factorization.

81065688057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111117 (or 111111 counting only the distinct ones).

The product of its (nonzero) digits is 3225600, while the sum is 54.

The spelling of 81065688057 in words is "eighty-one billion, sixty-five million, six hundred eighty-eight thousand, fifty-seven".