1311101223221 has 2 divisors, whose sum is σ = 1311101223222. Its totient is φ = 1311101223220.

The previous prime is 1311101223193. The next prime is 1311101223247. The reversal of 1311101223221 is 1223221011131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1193143320721 + 117957902500 = 1092311^2 + 343450^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311101223221 - 2¹⁸ = 1311100961077 is a prime.

It is a super-2 number, since 2×1311101223221² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1311101223193 and 1311101223202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311101223521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655550611610 + 655550611611.

It is an arithmetic number, because the mean of its divisors is an integer number (655550611611).

Almost surely, 2^{1311101223221} is an apocalyptic number.

It is an amenable number.

1311101223221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311101223221 is an equidigital number, since it uses as much as digits as its factorization.

1311101223221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1311101223221 its reverse (1223221011131), we get a palindrome (2534322234352).

The spelling of 1311101223221 in words is "one trillion, three hundred eleven billion, one hundred one million, two hundred twenty-three thousand, two hundred twenty-one".