211422221 has 2 divisors, whose sum is σ = 211422222. Its totient is φ = 211422220.

The previous prime is 211422203. The next prime is 211422223. The reversal of 211422221 is 122224112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162282121 + 49140100 = 12739^2 + 7010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211422221 is a prime.

Together with 211422223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211422221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211422223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105711110 + 105711111.

It is an arithmetic number, because the mean of its divisors is an integer number (105711111).

Almost surely, 2^211422221 is an apocalyptic number.

It is an amenable number.

211422221 is a deficient number, since it is larger than the sum of its proper divisors (1).

211422221 is an equidigital number, since it uses as much as digits as its factorization.

211422221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 17.

The square root of 211422221 is about 14540.3652292506. The cubic root of 211422221 is about 595.7310140417.

Adding to 211422221 its reverse (122224112), we get a palindrome (333646333).

The spelling of 211422221 in words is "two hundred eleven million, four hundred twenty-two thousand, two hundred twenty-one".