1211232121009 has 2 divisors, whose sum is σ = 1211232121010. Its totient is φ = 1211232121008.

The previous prime is 1211232120979. The next prime is 1211232121061. The reversal of 1211232121009 is 9001212321121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 790271216784 + 420960904225 = 888972^2 + 648815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211232121009 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211232121079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605616060504 + 605616060505.

It is an arithmetic number, because the mean of its divisors is an integer number (605616060505).

Almost surely, 2^{1211232121009} is an apocalyptic number.

It is an amenable number.

1211232121009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211232121009 is an equidigital number, since it uses as much as digits as its factorization.

1211232121009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 1211232121009 in words is "one trillion, two hundred eleven billion, two hundred thirty-two million, one hundred twenty-one thousand, nine".