221211111211 has 4 divisors (see below), whose sum is σ = 221229808000. Its totient is φ = 221192414424.

The previous prime is 221211111181. The next prime is 221211111227. The reversal of 221211111211 is 112111112122.

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

It is a cyclic number.

It is not a de Polignac number, because 221211111211 - 2⁹ = 221211110699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221211711211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9330636 + ... + 9354313.

It is an arithmetic number, because the mean of its divisors is an integer number (55307452000).

Almost surely, 2^221211111211 is an apocalyptic number.

221211111211 is a deficient number, since it is larger than the sum of its proper divisors (18696789).

221211111211 is a wasteful number, since it uses less digits than its factorization.

221211111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18696788.

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

Adding to 221211111211 its reverse (112111112122), we get a palindrome (333322223333).

The spelling of 221211111211 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred eleven thousand, two hundred eleven".