21220012211 has 4 divisors (see below), whose sum is σ = 21951736800. Its totient is φ = 20488287624.

The previous prime is 21220012207. The next prime is 21220012223. The reversal of 21220012211 is 11221002212.

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 21220012211 - 2² = 21220012207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220012201) 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 3 ways as a sum of consecutive naturals, for example, 365862251 + ... + 365862308.

It is an arithmetic number, because the mean of its divisors is an integer number (5487934200).

Almost surely, 2^21220012211 is an apocalyptic number.

21220012211 is a deficient number, since it is larger than the sum of its proper divisors (731724589).

21220012211 is an equidigital number, since it uses as much as digits as its factorization.

21220012211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731724588.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21220012211 its reverse (11221002212), we get a palindrome (32441014423).

Subtracting from 21220012211 its reverse (11221002212), we obtain a palindrome (9999009999).

It can be divided in two parts, 2122001 and 2211, that added together give a palindrome (2124212).

The spelling of 21220012211 in words is "twenty-one billion, two hundred twenty million, twelve thousand, two hundred eleven".