21222221111111 has 4 divisors (see below), whose sum is σ = 21223195210152. Its totient is φ = 21221247012072.

The previous prime is 21222221111107. The next prime is 21222221111129. The reversal of 21222221111111 is 11111112222212.

It is a happy number.

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 21222221111111 - 2² = 21222221111107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222221111011) 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, 487016840 + ... + 487060413.

It is an arithmetic number, because the mean of its divisors is an integer number (5305798802538).

Almost surely, 2^{21222221111111} is an apocalyptic number.

21222221111111 is a deficient number, since it is larger than the sum of its proper divisors (974099041).

21222221111111 is an equidigital number, since it uses as much as digits as its factorization.

21222221111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974099040.

The product of its digits is 64, while the sum is 20.

Adding to 21222221111111 its reverse (11111112222212), we get a palindrome (32333333333323).

The spelling of 21222221111111 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty-one million, one hundred eleven thousand, one hundred eleven".