31311123312281 has 2 divisors, whose sum is σ = 31311123312282. Its totient is φ = 31311123312280.

The previous prime is 31311123312043. The next prime is 31311123312389. The reversal of 31311123312281 is 18221332111313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29890221168025 + 1420902144256 = 5467195^2 + 1192016^2 .

It is an emirp because it is prime and its reverse (18221332111313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31311123312281 - 2³⁴ = 31293943443097 is a prime.

It is a super-2 number, since 2×31311123312281² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31311120312281) 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, 15655561656140 + 15655561656141.

It is an arithmetic number, because the mean of its divisors is an integer number (15655561656141).

Almost surely, 2^{31311123312281} is an apocalyptic number.

It is an amenable number.

31311123312281 is a deficient number, since it is larger than the sum of its proper divisors (1).

31311123312281 is an equidigital number, since it uses as much as digits as its factorization.

31311123312281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 32.

Adding to 31311123312281 its reverse (18221332111313), we get a palindrome (49532455423594).

The spelling of 31311123312281 in words is "thirty-one trillion, three hundred eleven billion, one hundred twenty-three million, three hundred twelve thousand, two hundred eighty-one".