12212211221 has 16 divisors (see below), whose sum is σ = 14788700160. Its totient is φ = 9850993200.

The previous prime is 12212211127. The next prime is 12212211223. The reversal of 12212211221 is 12211221221.

It is a cyclic number.

It is not a de Polignac number, because 12212211221 - 2¹⁸ = 12211949077 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12212211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12212211223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 283961 + ... + 324126.

It is an arithmetic number, because the mean of its divisors is an integer number (924293760).

Almost surely, 2^12212211221 is an apocalyptic number.

It is an amenable number.

12212211221 is a deficient number, since it is larger than the sum of its proper divisors (2576488939).

12212211221 is a wasteful number, since it uses less digits than its factorization.

12212211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608264.

The product of its digits is 64, while the sum is 17.

Adding to 12212211221 its reverse (12211221221), we get a palindrome (24423432442).

The spelling of 12212211221 in words is "twelve billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty-one".