221111111311 has 2 divisors, whose sum is σ = 221111111312. Its totient is φ = 221111111310.

The previous prime is 221111111237. The next prime is 221111111329. The reversal of 221111111311 is 113111111122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221111111311 - 2⁹ = 221111110799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221111111911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110555555655 + 110555555656.

It is an arithmetic number, because the mean of its divisors is an integer number (110555555656).

Almost surely, 2^221111111311 is an apocalyptic number.

221111111311 is a deficient number, since it is larger than the sum of its proper divisors (1).

221111111311 is an equidigital number, since it uses as much as digits as its factorization.

221111111311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12, while the sum is 16.

Adding to 221111111311 its reverse (113111111122), we get a palindrome (334222222433).

The spelling of 221111111311 in words is "two hundred twenty-one billion, one hundred eleven million, one hundred eleven thousand, three hundred eleven".