21201222211211 has 16 divisors (see below), whose sum is σ = 24297356031744. Its totient is φ = 18122000107104.

The previous prime is 21201222211199. The next prime is 21201222211223. The reversal of 21201222211211 is 11211222210212.

It is an interprime number because it is at equal distance from previous prime (21201222211199) and next prime (21201222211223).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201222211211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201222211231) 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, 1231256 + ... + 6627098.

It is an arithmetic number, because the mean of its divisors is an integer number (1518584751984).

Almost surely, 2^{21201222211211} is an apocalyptic number.

21201222211211 is a deficient number, since it is larger than the sum of its proper divisors (3096133820533).

21201222211211 is an equidigital number, since it uses as much as digits as its factorization.

21201222211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5397410.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21201222211211 its reverse (11211222210212), we get a palindrome (32412444421423).

Subtracting from 21201222211211 its reverse (11211222210212), we obtain a palindrome (9990000000999).

The spelling of 21201222211211 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, two hundred eleven thousand, two hundred eleven".