81742779996801 has 64 divisors (see below), whose sum is σ = 143047677542400. Its totient is φ = 40225532558400.

The previous prime is 81742779996799. The next prime is 81742779996847. The reversal of 81742779996801 is 10869997724718.

It is not a de Polignac number, because 81742779996801 - 2¹ = 81742779996799 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81742779996881) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 52956106 + ... + 54477836.

It is an arithmetic number, because the mean of its divisors is an integer number (2235119961600).

Almost surely, 2^{81742779996801} is an apocalyptic number.

It is an amenable number.

81742779996801 is a deficient number, since it is larger than the sum of its proper divisors (61304897545599).

81742779996801 is a wasteful number, since it uses less digits than its factorization.

81742779996801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534010.

The product of its (nonzero) digits is 768144384, while the sum is 78.

The spelling of 81742779996801 in words is "eighty-one trillion, seven hundred forty-two billion, seven hundred seventy-nine million, nine hundred ninety-six thousand, eight hundred one".