1311451113221 has 2 divisors, whose sum is σ = 1311451113222. Its totient is φ = 1311451113220.

The previous prime is 1311451113209. The next prime is 1311451113277. The reversal of 1311451113221 is 1223111541131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 959392824196 + 352058289025 = 979486^2 + 593345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311451113221 - 2¹⁸ = 1311450851077 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311451413221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655725556610 + 655725556611.

It is an arithmetic number, because the mean of its divisors is an integer number (655725556611).

Almost surely, 2^{1311451113221} is an apocalyptic number.

It is an amenable number.

1311451113221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311451113221 is an equidigital number, since it uses as much as digits as its factorization.

1311451113221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 26.

Adding to 1311451113221 its reverse (1223111541131), we get a palindrome (2534562654352).

The spelling of 1311451113221 in words is "one trillion, three hundred eleven billion, four hundred fifty-one million, one hundred thirteen thousand, two hundred twenty-one".