It is a self number, because there is not a number n which added to its sum of digits gives 81729266099696.
It is a congruent number.
It is an unprimeable number.
Almost surely, 281729266099696 is an apocalyptic number.
It is an amenable number.
81729266099696 is a wasteful number, since it uses less digits than its factorization.
81729266099696 is an odious number, because the sum of its binary digits is odd.
Adding to 81729266099696 its sum of digits (80), we get a square (81729266099776 = 90404242).
The spelling of 81729266099696 in words is "eighty-one trillion, seven hundred twenty-nine billion, two hundred sixty-six million, ninety-nine thousand, six hundred ninety-six".