31993915317 has 16 divisors (see below), whose sum is σ = 52502835840. Its totient is φ = 16875911232.

The previous prime is 31993915279. The next prime is 31993915321. The reversal of 31993915317 is 71351939913.

It is not a de Polignac number, because 31993915317 - 2¹⁵ = 31993882549 is a prime.

It is a super-2 number, since 2×31993915317² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31993915317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31993915337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58596642 + ... + 58597187.

It is an arithmetic number, because the mean of its divisors is an integer number (3281427240).

Almost surely, 2^31993915317 is an apocalyptic number.

It is an amenable number.

31993915317 is a deficient number, since it is larger than the sum of its proper divisors (20508920523).

31993915317 is a wasteful number, since it uses less digits than its factorization.

31993915317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117193852.

The product of its digits is 688905, while the sum is 51.

The spelling of 31993915317 in words is "thirty-one billion, nine hundred ninety-three million, nine hundred fifteen thousand, three hundred seventeen".