211221333209 has 2 divisors, whose sum is σ = 211221333210. Its totient is φ = 211221333208.

The previous prime is 211221333181. The next prime is 211221333251. The reversal of 211221333209 is 902333122112.

211221333209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207204308809 + 4017024400 = 455197^2 + 63380^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221333209 - 2⁸ = 211221332953 is a prime.

It is a super-2 number, since 2×211221333209² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211221333289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610666604 + 105610666605.

It is an arithmetic number, because the mean of its divisors is an integer number (105610666605).

Almost surely, 2^211221333209 is an apocalyptic number.

It is an amenable number.

211221333209 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221333209 is an equidigital number, since it uses as much as digits as its factorization.

211221333209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 29.

The spelling of 211221333209 in words is "two hundred eleven billion, two hundred twenty-one million, three hundred thirty-three thousand, two hundred nine".