21212011200209 has 2 divisors, whose sum is σ = 21212011200210. Its totient is φ = 21212011200208.

The previous prime is 21212011200199. The next prime is 21212011200227. The reversal of 21212011200209 is 90200211021212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20306379187600 + 905632012609 = 4506260^2 + 951647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212011200209 - 2¹² = 21212011196113 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212011200509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606005600104 + 10606005600105.

It is an arithmetic number, because the mean of its divisors is an integer number (10606005600105).

Almost surely, 2^{21212011200209} is an apocalyptic number.

It is an amenable number.

21212011200209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212011200209 is an equidigital number, since it uses as much as digits as its factorization.

21212011200209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 21212011200209 in words is "twenty-one trillion, two hundred twelve billion, eleven million, two hundred thousand, two hundred nine".