1221320111311 has 2 divisors, whose sum is σ = 1221320111312. Its totient is φ = 1221320111310.

The previous prime is 1221320111281. The next prime is 1221320111377. The reversal of 1221320111311 is 1131110231221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1131110231221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221320111311 - 2⁷ = 1221320111183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221320121311) 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, 610660055655 + 610660055656.

It is an arithmetic number, because the mean of its divisors is an integer number (610660055656).

Almost surely, 2^{1221320111311} is an apocalyptic number.

1221320111311 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221320111311 is an equidigital number, since it uses as much as digits as its factorization.

1221320111311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1221320111311 its reverse (1131110231221), we get a palindrome (2352430342532).

The spelling of 1221320111311 in words is "one trillion, two hundred twenty-one billion, three hundred twenty million, one hundred eleven thousand, three hundred eleven".