31312111331 has 4 divisors (see below), whose sum is σ = 31316124792. Its totient is φ = 31308097872.

The previous prime is 31312111319. The next prime is 31312111339. The reversal of 31312111331 is 13311121313.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31312111331 - 2¹⁸ = 31311849187 is a prime.

It is a super-2 number, since 2×31312111331² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31312111339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1995005 + ... + 2010638.

It is an arithmetic number, because the mean of its divisors is an integer number (7829031198).

Almost surely, 2^31312111331 is an apocalyptic number.

31312111331 is a deficient number, since it is larger than the sum of its proper divisors (4013461).

31312111331 is an equidigital number, since it uses as much as digits as its factorization.

31312111331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4013460.

The product of its digits is 162, while the sum is 20.

Adding to 31312111331 its reverse (13311121313), we get a palindrome (44623232644).

The spelling of 31312111331 in words is "thirty-one billion, three hundred twelve million, one hundred eleven thousand, three hundred thirty-one".