201221221009 has 2 divisors, whose sum is σ = 201221221010. Its totient is φ = 201221221008.

The previous prime is 201221220979. The next prime is 201221221027. The reversal of 201221221009 is 900122122102.

201221221009 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., 109542464784 + 91678756225 = 330972^2 + 302785^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221221009 - 2¹³ = 201221212817 is a prime.

It is not a weakly prime, because it can be changed into another prime (201221621009) 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, 100610610504 + 100610610505.

It is an arithmetic number, because the mean of its divisors is an integer number (100610610505).

Almost surely, 2^201221221009 is an apocalyptic number.

It is an amenable number.

201221221009 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221221009 is an equidigital number, since it uses as much as digits as its factorization.

201221221009 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 22.

The spelling of 201221221009 in words is "two hundred one billion, two hundred twenty-one million, two hundred twenty-one thousand, nine".