31013213112221 has 2 divisors, whose sum is σ = 31013213112222. Its totient is φ = 31013213112220.

The previous prime is 31013213112181. The next prime is 31013213112257. The reversal of 31013213112221 is 12221131231013.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27471330516100 + 3541882596121 = 5241310^2 + 1881989^2 .

It is a cyclic number.

It is not a de Polignac number, because 31013213112221 - 2²² = 31013208917917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31013213112121) 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, 15506606556110 + 15506606556111.

It is an arithmetic number, because the mean of its divisors is an integer number (15506606556111).

Almost surely, 2^{31013213112221} is an apocalyptic number.

It is an amenable number.

31013213112221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31013213112221 is an equidigital number, since it uses as much as digits as its factorization.

31013213112221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 31013213112221 its reverse (12221131231013), we get a palindrome (43234344343234).

The spelling of 31013213112221 in words is "thirty-one trillion, thirteen billion, two hundred thirteen million, one hundred twelve thousand, two hundred twenty-one".