81736688663718 has 64 divisors (see below), whose sum is σ = 183779549436672. Its totient is φ = 24017019108480.

The previous prime is 81736688663717. The next prime is 81736688663723.

81736688663718 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81736688663718² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81736688663717) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56402596 + ... + 57833607.

It is an arithmetic number, because the mean of its divisors is an integer number (2871555459948).

Almost surely, 2^{81736688663718} is an apocalyptic number.

81736688663718 is an abundant number, since it is smaller than the sum of its proper divisors (102042860772954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81736688663718 is a wasteful number, since it uses less digits than its factorization.

81736688663718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114236549.

The product of its digits is 2341011456, while the sum is 78.

The spelling of 81736688663718 in words is "eighty-one trillion, seven hundred thirty-six billion, six hundred eighty-eight million, six hundred sixty-three thousand, seven hundred eighteen".