21122211221111 has 32 divisors (see below), whose sum is σ = 28432797120000. Its totient is φ = 15153742961280.

The previous prime is 21122211221093. The next prime is 21122211221143. The reversal of 21122211221111 is 11112211222112.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21122211221111 is a prime.

It is a super-2 number, since 2×21122211221111² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122211221171) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26732861 + ... + 27511638.

It is an arithmetic number, because the mean of its divisors is an integer number (888524910000).

Almost surely, 2^{21122211221111} is an apocalyptic number.

21122211221111 is a deficient number, since it is larger than the sum of its proper divisors (7310585898889).

21122211221111 is a wasteful number, since it uses less digits than its factorization.

21122211221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54244919.

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

Adding to 21122211221111 its reverse (11112211222112), we get a palindrome (32234422443223).

The spelling of 21122211221111 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred eleven million, two hundred twenty-one thousand, one hundred eleven".