21122210111111 has 4 divisors (see below), whose sum is σ = 21122420334792. Its totient is φ = 21121999887432.

The previous prime is 21122210111089. The next prime is 21122210111173. The reversal of 21122210111111 is 11111101222112.

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 21122210111111 - 2¹⁰ = 21122210110087 is a prime.

It is a super-2 number, since 2×21122210111111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21122210111111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122210131111) 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, 104961056 + ... + 105162101.

It is an arithmetic number, because the mean of its divisors is an integer number (5280605083698).

Almost surely, 2^{21122210111111} is an apocalyptic number.

21122210111111 is a deficient number, since it is larger than the sum of its proper divisors (210223681).

21122210111111 is a wasteful number, since it uses less digits than its factorization.

21122210111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210223680.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 21122210111111 its reverse (11111101222112), we get a palindrome (32233311333223).

The spelling of 21122210111111 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred ten million, one hundred eleven thousand, one hundred eleven".