211231100209 has 2 divisors, whose sum is σ = 211231100210. Its totient is φ = 211231100208.

The previous prime is 211231100207. The next prime is 211231100219. The reversal of 211231100209 is 902001132112.

211231100209 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., 138460642609 + 72770457600 = 372103^2 + 269760^2 .

It is a cyclic number.

It is not a de Polignac number, because 211231100209 - 2¹ = 211231100207 is a prime.

Together with 211231100207, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 211231100209.

It is not a weakly prime, because it can be changed into another prime (211231100207) 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, 105615550104 + 105615550105.

It is an arithmetic number, because the mean of its divisors is an integer number (105615550105).

Almost surely, 2^211231100209 is an apocalyptic number.

It is an amenable number.

211231100209 is a deficient number, since it is larger than the sum of its proper divisors (1).

211231100209 is an equidigital number, since it uses as much as digits as its factorization.

211231100209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 211231100209 in words is "two hundred eleven billion, two hundred thirty-one million, one hundred thousand, two hundred nine".