11111212211 has 4 divisors (see below), whose sum is σ = 12121322424. Its totient is φ = 10101102000.

The previous prime is 11111212201. The next prime is 11111212213. The reversal of 11111212211 is 11221211111.

11111212211 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-11111212211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11111212213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505055090 + ... + 505055111.

It is an arithmetic number, because the mean of its divisors is an integer number (3030330606).

Almost surely, 2^11111212211 is an apocalyptic number.

11111212211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11111212211 is a deficient number, since it is larger than the sum of its proper divisors (1010110213).

11111212211 is a wasteful number, since it uses less digits than its factorization.

11111212211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010110212.

The product of its digits is 8, while the sum is 14.

Adding to 11111212211 its reverse (11221211111), we get a palindrome (22332423322).

It can be divided in two parts, 11111 and 212211, that added together give a palindrome (223322).

The spelling of 11111212211 in words is "eleven billion, one hundred eleven million, two hundred twelve thousand, two hundred eleven".