1211031212221 has 2 divisors, whose sum is σ = 1211031212222. Its totient is φ = 1211031212220.

The previous prime is 1211031212197. The next prime is 1211031212231. The reversal of 1211031212221 is 1222121301121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 804483424900 + 406547787321 = 896930^2 + 637611^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211031212221 - 2²⁷ = 1210896994493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211031212231) 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, 605515606110 + 605515606111.

It is an arithmetic number, because the mean of its divisors is an integer number (605515606111).

Almost surely, 2^{1211031212221} is an apocalyptic number.

It is an amenable number.

1211031212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211031212221 is an equidigital number, since it uses as much as digits as its factorization.

1211031212221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 1211031212221 its reverse (1222121301121), we get a palindrome (2433152513342).

The spelling of 1211031212221 in words is "one trillion, two hundred eleven billion, thirty-one million, two hundred twelve thousand, two hundred twenty-one".