212112212191909 has 2 divisors, whose sum is σ = 212112212191910. Its totient is φ = 212112212191908.

The previous prime is 212112212191853. The next prime is 212112212191921. The reversal of 212112212191909 is 909191212211212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212110969840900 + 1242351009 = 14564030^2 + 35247^2 .

It is a cyclic number.

It is not a de Polignac number, because 212112212191909 - 2¹¹ = 212112212189861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212112212191609) 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, 106056106095954 + 106056106095955.

It is an arithmetic number, because the mean of its divisors is an integer number (106056106095955).

Almost surely, 2^{212112212191909} is an apocalyptic number.

It is an amenable number.

212112212191909 is a deficient number, since it is larger than the sum of its proper divisors (1).

212112212191909 is an equidigital number, since it uses as much as digits as its factorization.

212112212191909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 43.

The spelling of 212112212191909 in words is "two hundred twelve trillion, one hundred twelve billion, two hundred twelve million, one hundred ninety-one thousand, nine hundred nine".