81540604518 has 16 divisors (see below), whose sum is σ = 164695875696. Its totient is φ = 26911090400.

The previous prime is 81540604517. The next prime is 81540604577.

81540604518 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 81540604518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540604517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67277121 + ... + 67278332.

It is an arithmetic number, because the mean of its divisors is an integer number (10293492231).

Almost surely, 2^81540604518 is an apocalyptic number.

81540604518 is an abundant number, since it is smaller than the sum of its proper divisors (83155271178).

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

81540604518 is a wasteful number, since it uses less digits than its factorization.

81540604518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134555559.

The product of its (nonzero) digits is 153600, while the sum is 42.

The spelling of 81540604518 in words is "eighty-one billion, five hundred forty million, six hundred four thousand, five hundred eighteen".