211111010221 has 2 divisors, whose sum is σ = 211111010222. Its totient is φ = 211111010220.

The previous prime is 211111010207. The next prime is 211111010237. The reversal of 211111010221 is 122010111112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156134829321 + 54976180900 = 395139^2 + 234470^2 .

It is a cyclic number.

It is not a de Polignac number, because 211111010221 - 2³³ = 202521075629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211111010521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105555505110 + 105555505111.

It is an arithmetic number, because the mean of its divisors is an integer number (105555505111).

Almost surely, 2^211111010221 is an apocalyptic number.

It is an amenable number.

211111010221 is a deficient number, since it is larger than the sum of its proper divisors (1).

211111010221 is an equidigital number, since it uses as much as digits as its factorization.

211111010221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 211111010221 its reverse (122010111112), we get a palindrome (333121121333).

The spelling of 211111010221 in words is "two hundred eleven billion, one hundred eleven million, ten thousand, two hundred twenty-one".