211994221 has 2 divisors, whose sum is σ = 211994222. Its totient is φ = 211994220.

The previous prime is 211994207. The next prime is 211994227. The reversal of 211994221 is 122499112.

It is a happy number.

211994221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112593321 + 99400900 = 10611^2 + 9970^2 .

It is a cyclic number.

It is not a de Polignac number, because 211994221 - 2¹⁹ = 211469933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211994227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105997110 + 105997111.

It is an arithmetic number, because the mean of its divisors is an integer number (105997111).

Almost surely, 2^211994221 is an apocalyptic number.

It is an amenable number.

211994221 is a deficient number, since it is larger than the sum of its proper divisors (1).

211994221 is an equidigital number, since it uses as much as digits as its factorization.

211994221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 31.

The square root of 211994221 is about 14560.0213255338. The cubic root of 211994221 is about 596.2677777019.

The spelling of 211994221 in words is "two hundred eleven million, nine hundred ninety-four thousand, two hundred twenty-one".