31013222111821 has 2 divisors, whose sum is σ = 31013222111822. Its totient is φ = 31013222111820.

The previous prime is 31013222111819. The next prime is 31013222111863. The reversal of 31013222111821 is 12811122231013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18397974389796 + 12615247722025 = 4289286^2 + 3551795^2 .

It is a cyclic number.

It is not a de Polignac number, because 31013222111821 - 2¹ = 31013222111819 is a prime.

Together with 31013222111819, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 31013222111821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31013222111021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15506611055910 + 15506611055911.

It is an arithmetic number, because the mean of its divisors is an integer number (15506611055911).

Almost surely, 2^{31013222111821} is an apocalyptic number.

It is an amenable number.

31013222111821 is a deficient number, since it is larger than the sum of its proper divisors (1).

31013222111821 is an equidigital number, since it uses as much as digits as its factorization.

31013222111821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

Adding to 31013222111821 its reverse (12811122231013), we get a palindrome (43824344342834).

The spelling of 31013222111821 in words is "thirty-one trillion, thirteen billion, two hundred twenty-two million, one hundred eleven thousand, eight hundred twenty-one".