11111121211 has 2 divisors, whose sum is σ = 11111121212. Its totient is φ = 11111121210.

The previous prime is 11111121209. The next prime is 11111121247. The reversal of 11111121211 is 11212111111.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11111121211 - 2¹ = 11111121209 is a prime.

Together with 11111121209, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 11111121191 and 11111121200.

It is not a weakly prime, because it can be changed into another prime (11111121271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555560605 + 5555560606.

It is an arithmetic number, because the mean of its divisors is an integer number (5555560606).

Almost surely, 2^11111121211 is an apocalyptic number.

11111121211 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111121211 is an equidigital number, since it uses as much as digits as its factorization.

11111121211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4, while the sum is 13.

Adding to 11111121211 its reverse (11212111111), we get a palindrome (22323232322).

It can be divided in two parts, 1111 and 1121211, that multiplied together give a palindrome (1245665421).

The spelling of 11111121211 in words is "eleven billion, one hundred eleven million, one hundred twenty-one thousand, two hundred eleven".