11555221211 has 2 divisors, whose sum is σ = 11555221212. Its totient is φ = 11555221210.

The previous prime is 11555221193. The next prime is 11555221219. The reversal of 11555221211 is 11212255511.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11555221211 - 2²⁶ = 11488112347 is a prime.

It is not a weakly prime, because it can be changed into another prime (11555221219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5777610605 + 5777610606.

It is an arithmetic number, because the mean of its divisors is an integer number (5777610606).

Almost surely, 2^11555221211 is an apocalyptic number.

11555221211 is a deficient number, since it is larger than the sum of its proper divisors (1).

11555221211 is an equidigital number, since it uses as much as digits as its factorization.

11555221211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1000, while the sum is 26.

Adding to 11555221211 its reverse (11212255511), we get a palindrome (22767476722).

The spelling of 11555221211 in words is "eleven billion, five hundred fifty-five million, two hundred twenty-one thousand, two hundred eleven".