210221001209 has 2 divisors, whose sum is σ = 210221001210. Its totient is φ = 210221001208.

The previous prime is 210221001163. The next prime is 210221001223. The reversal of 210221001209 is 902100122012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180013518400 + 30207482809 = 424280^2 + 173803^2 .

It is a cyclic number.

It is not a de Polignac number, because 210221001209 - 2⁸ = 210221000953 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (210221001269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105110500604 + 105110500605.

It is an arithmetic number, because the mean of its divisors is an integer number (105110500605).

Almost surely, 2^210221001209 is an apocalyptic number.

It is an amenable number.

210221001209 is a deficient number, since it is larger than the sum of its proper divisors (1).

210221001209 is an equidigital number, since it uses as much as digits as its factorization.

210221001209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 210221001209 in words is "two hundred ten billion, two hundred twenty-one million, one thousand, two hundred nine".