31121312313 has 96 divisors (see below), whose sum is σ = 52968784896. Its totient is φ = 15902625024.

The previous prime is 31121312309. The next prime is 31121312407. The reversal of 31121312313 is 31321312113.

It is a happy number.

It is not a de Polignac number, because 31121312313 - 2² = 31121312309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31121312313.

It is not an unprimeable number, because it can be changed into a prime (31121312303) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 45565270 + ... + 45565952.

It is an arithmetic number, because the mean of its divisors is an integer number (551758176).

Almost surely, 2^31121312313 is an apocalyptic number.

It is an amenable number.

31121312313 is a deficient number, since it is larger than the sum of its proper divisors (21847472583).

31121312313 is a wasteful number, since it uses less digits than its factorization.

31121312313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103 (or 1090 counting only the distinct ones).

The product of its digits is 324, while the sum is 21.

Adding to 31121312313 its reverse (31321312113), we get a palindrome (62442624426).

The spelling of 31121312313 in words is "thirty-one billion, one hundred twenty-one million, three hundred twelve thousand, three hundred thirteen".