21112012222111 has 4 divisors (see below), whose sum is σ = 21469842937800. Its totient is φ = 20754181506424.

The previous prime is 21112012222087. The next prime is 21112012222123. The reversal of 21112012222111 is 11122221021112.

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 21112012222111 - 2⁴¹ = 18912988966559 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 (21112012222141) 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, 178915357756 + ... + 178915357873.

It is an arithmetic number, because the mean of its divisors is an integer number (5367460734450).

Almost surely, 2^{21112012222111} is an apocalyptic number.

21112012222111 is a deficient number, since it is larger than the sum of its proper divisors (357830715689).

21112012222111 is an equidigital number, since it uses as much as digits as its factorization.

21112012222111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357830715688.

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

Adding to 21112012222111 its reverse (11122221021112), we get a palindrome (32234233243223).

The spelling of 21112012222111 in words is "twenty-one trillion, one hundred twelve billion, twelve million, two hundred twenty-two thousand, one hundred eleven".