81729266099597 has 2 divisors, whose sum is σ = 81729266099598. Its totient is φ = 81729266099596.

The previous prime is 81729266099531. The next prime is 81729266099603. The reversal of 81729266099597 is 79599066292718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80053926765796 + 1675339333801 = 8947286^2 + 1294349^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81729266099597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81729266009597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40864633049798 + 40864633049799.

It is an arithmetic number, because the mean of its divisors is an integer number (40864633049799).

Almost surely, 2^{81729266099597} is an apocalyptic number.

It is an amenable number.

81729266099597 is a deficient number, since it is larger than the sum of its proper divisors (1).

81729266099597 is an equidigital number, since it uses as much as digits as its factorization.

81729266099597 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1851776640, while the sum is 80.

The spelling of 81729266099597 in words is "eighty-one trillion, seven hundred twenty-nine billion, two hundred sixty-six million, ninety-nine thousand, five hundred ninety-seven".