221221101209 has 2 divisors, whose sum is σ = 221221101210. Its totient is φ = 221221101208.

The previous prime is 221221101203. The next prime is 221221101229. The reversal of 221221101209 is 902101122122.

221221101209 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., 218537550400 + 2683550809 = 467480^2 + 51803^2 .

It is a cyclic number.

It is not a de Polignac number, because 221221101209 - 2⁴ = 221221101193 is a prime.

It is not a weakly prime, because it can be changed into another prime (221221101203) 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, 110610550604 + 110610550605.

It is an arithmetic number, because the mean of its divisors is an integer number (110610550605).

Almost surely, 2^221221101209 is an apocalyptic number.

It is an amenable number.

221221101209 is a deficient number, since it is larger than the sum of its proper divisors (1).

221221101209 is an equidigital number, since it uses as much as digits as its factorization.

221221101209 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 221221101209 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, two hundred nine".