81173047285 has 16 divisors (see below), whose sum is σ = 106280475840. Its totient is φ = 59025178240.

The previous prime is 81173047231. The next prime is 81173047289. The reversal of 81173047285 is 58274037118.

It is not a de Polignac number, because 81173047285 - 2¹⁹ = 81172522997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81173047289) 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, 222201 + ... + 460129.

It is an arithmetic number, because the mean of its divisors is an integer number (6642529740).

Almost surely, 2^81173047285 is an apocalyptic number.

It is an amenable number.

81173047285 is a deficient number, since it is larger than the sum of its proper divisors (25107428555).

81173047285 is a wasteful number, since it uses less digits than its factorization.

81173047285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244148.

The product of its (nonzero) digits is 376320, while the sum is 46.

The spelling of 81173047285 in words is "eighty-one billion, one hundred seventy-three million, forty-seven thousand, two hundred eighty-five".