81729266099775 has 48 divisors (see below), whose sum is σ = 154430794963200. Its totient is φ = 37361611330560.

The previous prime is 81729266099743. The next prime is 81729266099777. The reversal of 81729266099775 is 57799066292718.

It is a Cunningham number, because it is equal to 9040424²-1.

It is not a de Polignac number, because 81729266099775 - 2⁵ = 81729266099743 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81729266099775.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81729266099777) 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, 62637231 + ... + 63928719.

It is an arithmetic number, because the mean of its divisors is an integer number (3217308228400).

Almost surely, 2^{81729266099775} is an apocalyptic number.

81729266099775 is a deficient number, since it is larger than the sum of its proper divisors (72701528863425).

81729266099775 is a wasteful number, since it uses less digits than its factorization.

81729266099775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1412048 (or 1412043 counting only the distinct ones).

The product of its (nonzero) digits is 1440270720, while the sum is 78.

The spelling of 81729266099775 in words is "eighty-one trillion, seven hundred twenty-nine billion, two hundred sixty-six million, ninety-nine thousand, seven hundred seventy-five".