81313311331318 has 16 divisors (see below), whose sum is σ = 133063729610256. Its totient is φ = 36959045005440.

The previous prime is 81313311331249. The next prime is 81313311331387.

It is a happy number.

81313311331318 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (81313311331249) and next prime (81313311331387).

It is a super-4 number, since 4×81313311331318⁴ (a number of 57 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

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, 77016471 + ... + 78065122.

It is an arithmetic number, because the mean of its divisors is an integer number (8316483100641).

Almost surely, 2^{81313311331318} is an apocalyptic number.

81313311331318 is a deficient number, since it is larger than the sum of its proper divisors (51750418278938).

81313311331318 is a wasteful number, since it uses less digits than its factorization.

81313311331318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155105439.

The product of its digits is 46656, while the sum is 40.

It can be divided in two parts, 8131331 and 1331318, that added together give a palindrome (9462649).

The spelling of 81313311331318 in words is "eighty-one trillion, three hundred thirteen billion, three hundred eleven million, three hundred thirty-one thousand, three hundred eighteen".