31311312212251 has 2 divisors, whose sum is σ = 31311312212252. Its totient is φ = 31311312212250.

The previous prime is 31311312212177. The next prime is 31311312212311. The reversal of 31311312212251 is 15221221311313.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31311312212251 - 2²³ = 31311303823643 is a prime.

It is a super-2 number, since 2×31311312212251² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31311312912251) 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, 15655656106125 + 15655656106126.

It is an arithmetic number, because the mean of its divisors is an integer number (15655656106126).

Almost surely, 2^{31311312212251} is an apocalyptic number.

31311312212251 is a deficient number, since it is larger than the sum of its proper divisors (1).

31311312212251 is an equidigital number, since it uses as much as digits as its factorization.

31311312212251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

Adding to 31311312212251 its reverse (15221221311313), we get a palindrome (46532533523564).

The spelling of 31311312212251 in words is "thirty-one trillion, three hundred eleven billion, three hundred twelve million, two hundred twelve thousand, two hundred fifty-one".