12211221111 has 32 divisors (see below), whose sum is σ = 17464785408. Its totient is φ = 7569429120.

The previous prime is 12211221109. The next prime is 12211221151. The reversal of 12211221111 is 11112211221.

It is a happy number.

It is not a de Polignac number, because 12211221111 - 2¹ = 12211221109 is a prime.

It is a super-2 number, since 2×12211221111² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12211221151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4928605 + ... + 4931081.

It is an arithmetic number, because the mean of its divisors is an integer number (545774544).

Almost surely, 2^12211221111 is an apocalyptic number.

12211221111 is a deficient number, since it is larger than the sum of its proper divisors (5253564297).

12211221111 is a wasteful number, since it uses less digits than its factorization.

12211221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4471.

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

Adding to 12211221111 its reverse (11112211221), we get a palindrome (23323432332).

It can be divided in two parts, 12211221 and 111, that multiplied together give a palindrome (1355445531).

The spelling of 12211221111 in words is "twelve billion, two hundred eleven million, two hundred twenty-one thousand, one hundred eleven".