221211201209 has 2 divisors, whose sum is σ = 221211201210. Its totient is φ = 221211201208.

The previous prime is 221211201151. The next prime is 221211201221. The reversal of 221211201209 is 902102112122.

221211201209 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., 220967685184 + 243516025 = 470072^2 + 15605^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211201209 - 2¹² = 221211197113 is a prime.

It is not a weakly prime, because it can be changed into another prime (221211207209) 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, 110605600604 + 110605600605.

It is an arithmetic number, because the mean of its divisors is an integer number (110605600605).

Almost surely, 2^221211201209 is an apocalyptic number.

It is an amenable number.

221211201209 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211201209 is an equidigital number, since it uses as much as digits as its factorization.

221211201209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 221211201209 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred one thousand, two hundred nine".