81706760928591 has 32 divisors (see below), whose sum is σ = 119355480469440. Its totient is φ = 49487898679296.

The previous prime is 81706760928563. The next prime is 81706760928601. The reversal of 81706760928591 is 19582906760718.

It is not a de Polignac number, because 81706760928591 - 2¹³ = 81706760920399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81706760928491) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 221085 + ... + 12785241.

It is an arithmetic number, because the mean of its divisors is an integer number (3729858764670).

Almost surely, 2^{81706760928591} is an apocalyptic number.

81706760928591 is a deficient number, since it is larger than the sum of its proper divisors (37648719540849).

81706760928591 is a wasteful number, since it uses less digits than its factorization.

81706760928591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12568603.

The product of its (nonzero) digits is 91445760, while the sum is 69.

The spelling of 81706760928591 in words is "eighty-one trillion, seven hundred six billion, seven hundred sixty million, nine hundred twenty-eight thousand, five hundred ninety-one".