222211211211221 has 4 divisors (see below), whose sum is σ = 222224040234444. Its totient is φ = 222198382188000.

The previous prime is 222211211211217. The next prime is 222211211211239. The reversal of 222211211211221 is 122112112112222.

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

It can be written as a sum of positive squares in 2 ways, for example, as 147805146660196 + 74406064551025 = 12157514^2 + 8625895^2 .

It is a cyclic number.

It is not a de Polignac number, because 222211211211221 - 2² = 222211211211217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222211211211211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6414485630 + ... + 6414520271.

It is an arithmetic number, because the mean of its divisors is an integer number (55556010058611).

Almost surely, 2^{222211211211221} is an apocalyptic number.

It is an amenable number.

222211211211221 is a deficient number, since it is larger than the sum of its proper divisors (12829023223).

222211211211221 is a wasteful number, since it uses less digits than its factorization.

222211211211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12829023222.

The product of its digits is 256, while the sum is 23.

Adding to 222211211211221 its reverse (122112112112222), we get a palindrome (344323323323443).

The spelling of 222211211211221 in words is "two hundred twenty-two trillion, two hundred eleven billion, two hundred eleven million, two hundred eleven thousand, two hundred twenty-one".