81623511532618 has 32 divisors (see below), whose sum is σ = 135386634240000. Its totient is φ = 36596697948720.

The previous prime is 81623511532613. The next prime is 81623511532657.

It is a happy number.

81623511532618 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (81623511532613) 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 15 ways as a sum of consecutive naturals, for example, 20794818 + ... + 24406381.

It is an arithmetic number, because the mean of its divisors is an integer number (4230832320000).

Almost surely, 2^{81623511532618} is an apocalyptic number.

81623511532618 is a deficient number, since it is larger than the sum of its proper divisors (53763122707382).

81623511532618 is a wasteful number, since it uses less digits than its factorization.

81623511532618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45202330.

The product of its digits is 2073600, while the sum is 52.

It can be divided in two parts, 8162351 and 1532618, that added together give a palindrome (9694969).

The spelling of 81623511532618 in words is "eighty-one trillion, six hundred twenty-three billion, five hundred eleven million, five hundred thirty-two thousand, six hundred eighteen".