81728207275239 has 48 divisors (see below), whose sum is σ = 135495302342400. Its totient is φ = 46501758840960.

The previous prime is 81728207275193. The next prime is 81728207275241. The reversal of 81728207275239 is 93257270282718.

81728207275239 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 82 + 0 + 7 + 27 + 523 + 9 = 666.

It is not a de Polignac number, because 81728207275239 - 2⁸ = 81728207274983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81728207275639) 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, 16604187 + ... + 20956035.

It is an arithmetic number, because the mean of its divisors is an integer number (2822818798800).

Almost surely, 2^{81728207275239} is an apocalyptic number.

81728207275239 is a deficient number, since it is larger than the sum of its proper divisors (53767095067161).

81728207275239 is a wasteful number, since it uses less digits than its factorization.

81728207275239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4353140 (or 4353137 counting only the distinct ones).

The product of its (nonzero) digits is 47416320, while the sum is 63.

The spelling of 81728207275239 in words is "eighty-one trillion, seven hundred twenty-eight billion, two hundred seven million, two hundred seventy-five thousand, two hundred thirty-nine".