212122121209 has 2 divisors, whose sum is σ = 212122121210. Its totient is φ = 212122121208.

The previous prime is 212122121207. The next prime is 212122121251. The reversal of 212122121209 is 902121221212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164085755625 + 48036365584 = 405075^2 + 219172^2 .

It is a cyclic number.

It is not a de Polignac number, because 212122121209 - 2¹ = 212122121207 is a prime.

Together with 212122121207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (212122121207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106061060604 + 106061060605.

It is an arithmetic number, because the mean of its divisors is an integer number (106061060605).

Almost surely, 2^212122121209 is an apocalyptic number.

It is an amenable number.

212122121209 is a deficient number, since it is larger than the sum of its proper divisors (1).

212122121209 is an equidigital number, since it uses as much as digits as its factorization.

212122121209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 212122121209 in words is "two hundred twelve billion, one hundred twenty-two million, one hundred twenty-one thousand, two hundred nine".