211221212221111 has 2 divisors, whose sum is σ = 211221212221112. Its totient is φ = 211221212221110.

The previous prime is 211221212221051. The next prime is 211221212221147. The reversal of 211221212221111 is 111122212122112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211221212221111 is a prime.

It is a super-2 number, since 2×211221212221111² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211221212227111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610606110555 + 105610606110556.

It is an arithmetic number, because the mean of its divisors is an integer number (105610606110556).

Almost surely, 2^{211221212221111} is an apocalyptic number.

211221212221111 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221212221111 is an equidigital number, since it uses as much as digits as its factorization.

211221212221111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 22.

Adding to 211221212221111 its reverse (111122212122112), we get a palindrome (322343424343223).

The spelling of 211221212221111 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred eleven".