81313031317 has 16 divisors (see below), whose sum is σ = 94113374080. Its totient is φ = 68813260992.

The previous prime is 81313031309. The next prime is 81313031333. The reversal of 81313031317 is 71313031318.

It is not a de Polignac number, because 81313031317 - 2³ = 81313031309 is a prime.

It is a super-2 number, since 2×81313031317² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81313031417) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27643 + ... + 404215.

It is an arithmetic number, because the mean of its divisors is an integer number (5882085880).

Almost surely, 2^81313031317 is an apocalyptic number.

It is an amenable number.

81313031317 is a deficient number, since it is larger than the sum of its proper divisors (12800342763).

81313031317 is a wasteful number, since it uses less digits than its factorization.

81313031317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376972.

The product of its (nonzero) digits is 4536, while the sum is 31.

Subtracting from 81313031317 its reverse (71313031318), we obtain a palindrome (9999999999).

The spelling of 81313031317 in words is "eighty-one billion, three hundred thirteen million, thirty-one thousand, three hundred seventeen".