1211122001809 has 2 divisors, whose sum is σ = 1211122001810. Its totient is φ = 1211122001808.

The previous prime is 1211122001759. The next prime is 1211122001827. The reversal of 1211122001809 is 9081002211121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1147351611025 + 63770390784 = 1071145^2 + 252528^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211122001809 - 2¹⁷ = 1211121870737 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211122001899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605561000904 + 605561000905.

It is an arithmetic number, because the mean of its divisors is an integer number (605561000905).

Almost surely, 2^{1211122001809} is an apocalyptic number.

It is an amenable number.

1211122001809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211122001809 is an equidigital number, since it uses as much as digits as its factorization.

1211122001809 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 28.

The spelling of 1211122001809 in words is "one trillion, two hundred eleven billion, one hundred twenty-two million, one thousand, eight hundred nine".