21222111021211 has 4 divisors (see below), whose sum is σ = 21222135883624. Its totient is φ = 21222086158800.

The previous prime is 21222111021193. The next prime is 21222111021233. The reversal of 21222111021211 is 11212011122212.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21222111021211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21222111028211) 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, 11103570 + ... + 12873751.

It is an arithmetic number, because the mean of its divisors is an integer number (5305533970906).

Almost surely, 2^{21222111021211} is an apocalyptic number.

21222111021211 is a deficient number, since it is larger than the sum of its proper divisors (24862413).

21222111021211 is an equidigital number, since it uses as much as digits as its factorization.

21222111021211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24862412.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21222111021211 its reverse (11212011122212), we get a palindrome (32434122143423).

The spelling of 21222111021211 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, twenty-one thousand, two hundred eleven".