81356465318 has 4 divisors (see below), whose sum is σ = 122034697980. Its totient is φ = 40678232658.

The previous prime is 81356465299. The next prime is 81356465363.

81356465318 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×81356465318² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20339116328 + ... + 20339116331.

It is an arithmetic number, because the mean of its divisors is an integer number (30508674495).

Almost surely, 2^81356465318 is an apocalyptic number.

81356465318 is a deficient number, since it is larger than the sum of its proper divisors (40678232662).

81356465318 is a wasteful number, since it uses less digits than its factorization.

81356465318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40678232661.

The product of its digits is 2073600, while the sum is 50.

The spelling of 81356465318 in words is "eighty-one billion, three hundred fifty-six million, four hundred sixty-five thousand, three hundred eighteen".