11212221111 has 48 divisors (see below), whose sum is σ = 19234391904. Its totient is φ = 5754260736.

The previous prime is 11212221107. The next prime is 11212221121. The reversal of 11212221111 is 11112221211.

It is a happy number.

It is not a de Polignac number, because 11212221111 - 2² = 11212221107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11212221121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8580 + ... + 149993.

It is an arithmetic number, because the mean of its divisors is an integer number (400716498).

Almost surely, 2^11212221111 is an apocalyptic number.

11212221111 is a deficient number, since it is larger than the sum of its proper divisors (8022170793).

11212221111 is a wasteful number, since it uses less digits than its factorization.

11212221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158640 (or 158633 counting only the distinct ones).

The product of its digits is 16, while the sum is 15.

Adding to 11212221111 its reverse (11112221211), we get a palindrome (22324442322).

The spelling of 11212221111 in words is "eleven billion, two hundred twelve million, two hundred twenty-one thousand, one hundred eleven".