21211123321111 has 2 divisors, whose sum is σ = 21211123321112. Its totient is φ = 21211123321110.

The previous prime is 21211123321043. The next prime is 21211123321133. The reversal of 21211123321111 is 11112332111212.

It is an a-pointer prime, because the next prime (21211123321133) can be obtained adding 21211123321111 to its sum of digits (22).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211123321111 - 2³³ = 21202533386519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211123321151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605561660555 + 10605561660556.

It is an arithmetic number, because the mean of its divisors is an integer number (10605561660556).

Almost surely, 2^{21211123321111} is an apocalyptic number.

21211123321111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211123321111 is an equidigital number, since it uses as much as digits as its factorization.

21211123321111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 22.

Adding to 21211123321111 its reverse (11112332111212), we get a palindrome (32323455432323).

The spelling of 21211123321111 in words is "twenty-one trillion, two hundred eleven billion, one hundred twenty-three million, three hundred twenty-one thousand, one hundred eleven".