31313231393 has 2 divisors, whose sum is σ = 31313231394. Its totient is φ = 31313231392.

The previous prime is 31313231363. The next prime is 31313231399. The reversal of 31313231393 is 39313231313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29820799969 + 1492431424 = 172687^2 + 38632^2 .

It is a cyclic number.

It is not a de Polignac number, because 31313231393 - 2¹⁰ = 31313230369 is a prime.

It is not a weakly prime, because it can be changed into another prime (31313231399) 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 as a sum of consecutive naturals, namely, 15656615696 + 15656615697.

It is an arithmetic number, because the mean of its divisors is an integer number (15656615697).

Almost surely, 2^31313231393 is an apocalyptic number.

It is an amenable number.

31313231393 is a deficient number, since it is larger than the sum of its proper divisors (1).

31313231393 is an equidigital number, since it uses as much as digits as its factorization.

31313231393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13122, while the sum is 32.

The spelling of 31313231393 in words is "thirty-one billion, three hundred thirteen million, two hundred thirty-one thousand, three hundred ninety-three".