81321344312318 has 16 divisors (see below), whose sum is σ = 133071966892800. Its totient is φ = 36964059581400.

The previous prime is 81321344312297. The next prime is 81321344312323.

It is a happy number.

81321344312318 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81321344312318² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4916438 + ... + 13667993.

It is an arithmetic number, because the mean of its divisors is an integer number (8316997930800).

Almost surely, 2^{81321344312318} is an apocalyptic number.

81321344312318 is a deficient number, since it is larger than the sum of its proper divisors (51750622580482).

81321344312318 is a wasteful number, since it uses less digits than its factorization.

81321344312318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18783343.

The product of its digits is 331776, while the sum is 44.

The spelling of 81321344312318 in words is "eighty-one trillion, three hundred twenty-one billion, three hundred forty-four million, three hundred twelve thousand, three hundred eighteen".