31313323121 has 2 divisors, whose sum is σ = 31313323122. Its totient is φ = 31313323120.

The previous prime is 31313323031. The next prime is 31313323133. The reversal of 31313323121 is 12132331313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29191431025 + 2121892096 = 170855^2 + 46064^2 .

It is a cyclic number.

It is not a de Polignac number, because 31313323121 - 2²⁶ = 31246214257 is a prime.

It is not a weakly prime, because it can be changed into another prime (31313323421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656661560 + 15656661561.

It is an arithmetic number, because the mean of its divisors is an integer number (15656661561).

Almost surely, 2^31313323121 is an apocalyptic number.

It is an amenable number.

31313323121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31313323121 is an equidigital number, since it uses as much as digits as its factorization.

31313323121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 23.

Adding to 31313323121 its reverse (12132331313), we get a palindrome (43445654434).

The spelling of 31313323121 in words is "thirty-one billion, three hundred thirteen million, three hundred twenty-three thousand, one hundred twenty-one".