2121121212209 has 2 divisors, whose sum is σ = 2121121212210. Its totient is φ = 2121121212208.

The previous prime is 2121121212193. The next prime is 2121121212277. The reversal of 2121121212209 is 9022121211212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2119542898225 + 1578313984 = 1455865^2 + 39728^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121121212209 - 2⁴ = 2121121212193 is a prime.

It is a super-2 number, since 2×2121121212209² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2121121217209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060560606104 + 1060560606105.

It is an arithmetic number, because the mean of its divisors is an integer number (1060560606105).

Almost surely, 2^{2121121212209} is an apocalyptic number.

It is an amenable number.

2121121212209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121121212209 is an equidigital number, since it uses as much as digits as its factorization.

2121121212209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 2121121212209 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-one million, two hundred twelve thousand, two hundred nine".