21212201202209 has 2 divisors, whose sum is σ = 21212201202210. Its totient is φ = 21212201202208.

The previous prime is 21212201202193. The next prime is 21212201202251. The reversal of 21212201202209 is 90220210221212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20398727085025 + 813474117184 = 4516495^2 + 901928^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212201202209 - 2⁴ = 21212201202193 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212201202299) 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, 10606100601104 + 10606100601105.

It is an arithmetic number, because the mean of its divisors is an integer number (10606100601105).

Almost surely, 2^{21212201202209} is an apocalyptic number.

It is an amenable number.

21212201202209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212201202209 is an equidigital number, since it uses as much as digits as its factorization.

21212201202209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 21212201202209 in words is "twenty-one trillion, two hundred twelve billion, two hundred one million, two hundred two thousand, two hundred nine".