81815433451818 has 16 divisors (see below), whose sum is σ = 178506400258656. Its totient is φ = 24792555591440.

The previous prime is 81815433451811. The next prime is 81815433451819.

81815433451818 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (81815433451811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 619813889721 + ... + 619813889852.

It is an arithmetic number, because the mean of its divisors is an integer number (11156650016166).

Almost surely, 2^{81815433451818} is an apocalyptic number.

81815433451818 is an abundant number, since it is smaller than the sum of its proper divisors (96690966806838).

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

81815433451818 is a wasteful number, since it uses less digits than its factorization.

81815433451818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1239627779589.

The product of its digits is 14745600, while the sum is 60.

The spelling of 81815433451818 in words is "eighty-one trillion, eight hundred fifteen billion, four hundred thirty-three million, four hundred fifty-one thousand, eight hundred eighteen".