212209 has 2 divisors, whose sum is σ = 212210. Its totient is φ = 212208.

The previous prime is 212207. The next prime is 212227. The reversal of 212209 is 902212.

It is a happy number.

212209 is nontrivially palindromic in base 15.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207025 + 5184 = 455^2 + 72^2 .

It is a cyclic number.

It is not a de Polignac number, because 212209 - 2¹ = 212207 is a prime.

Together with 212207, it forms a pair of twin primes.

It is an Ulam number.

212209 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 212192 and 212201.

It is not a weakly prime, because it can be changed into another prime (212203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106104 + 106105.

It is an arithmetic number, because the mean of its divisors is an integer number (106105).

2²¹²²⁰⁹ is an apocalyptic number.

It is an amenable number.

212209 is a deficient number, since it is larger than the sum of its proper divisors (1).

212209 is an equidigital number, since it uses as much as digits as its factorization.

212209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 212209 is about 460.6614809163. The cubic root of 212209 is about 59.6469076541.

The spelling of 212209 in words is "two hundred twelve thousand, two hundred nine".