12123542009 has 2 divisors, whose sum is σ = 12123542010. Its totient is φ = 12123542008.

The previous prime is 12123541999. The next prime is 12123542033. The reversal of 12123542009 is 90024532121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10785445609 + 1338096400 = 103853^2 + 36580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12123542009 is a prime.

It is not a weakly prime, because it can be changed into another prime (12123542069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6061771004 + 6061771005.

It is an arithmetic number, because the mean of its divisors is an integer number (6061771005).

Almost surely, 2^12123542009 is an apocalyptic number.

It is an amenable number.

12123542009 is a deficient number, since it is larger than the sum of its proper divisors (1).

12123542009 is an equidigital number, since it uses as much as digits as its factorization.

12123542009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The spelling of 12123542009 in words is "twelve billion, one hundred twenty-three million, five hundred forty-two thousand, nine".