31131312031 has 2 divisors, whose sum is σ = 31131312032. Its totient is φ = 31131312030.

The previous prime is 31131312011. The next prime is 31131312049. The reversal of 31131312031 is 13021313113.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31131312031 - 2¹¹ = 31131309983 is a prime.

It is a super-2 number, since 2×31131312031² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31131312011) 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 as a sum of consecutive naturals, namely, 15565656015 + 15565656016.

It is an arithmetic number, because the mean of its divisors is an integer number (15565656016).

Almost surely, 2^31131312031 is an apocalyptic number.

31131312031 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131312031 is an equidigital number, since it uses as much as digits as its factorization.

31131312031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 31131312031 its reverse (13021313113), we get a palindrome (44152625144).

The spelling of 31131312031 in words is "thirty-one billion, one hundred thirty-one million, three hundred twelve thousand, thirty-one".