81313031318 has 16 divisors (see below), whose sum is σ = 124373092896. Its totient is φ = 39863150400.

The previous prime is 81313031309. The next prime is 81313031333.

81313031318 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81313031318² (a number of 23 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, 1933271 + ... + 1974882.

It is an arithmetic number, because the mean of its divisors is an integer number (7773318306).

Almost surely, 2^81313031318 is an apocalyptic number.

81313031318 is a deficient number, since it is larger than the sum of its proper divisors (43060061578).

81313031318 is a wasteful number, since it uses less digits than its factorization.

81313031318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3908359.

The product of its (nonzero) digits is 5184, while the sum is 32.

It can be divided in two parts, 813130 and 31318, that added together give a palindrome (844448).

The spelling of 81313031318 in words is "eighty-one billion, three hundred thirteen million, thirty-one thousand, three hundred eighteen".