12531809 has 2 divisors, whose sum is σ = 12531810. Its totient is φ = 12531808.

The previous prime is 12531787. The next prime is 12531829. The reversal of 12531809 is 90813521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9120400 + 3411409 = 3020^2 + 1847^2 .

It is a cyclic number.

It is not a de Polignac number, because 12531809 - 2⁸ = 12531553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12531829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6265904 + 6265905.

It is an arithmetic number, because the mean of its divisors is an integer number (6265905).

Almost surely, 2^12531809 is an apocalyptic number.

It is an amenable number.

12531809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12531809 is an equidigital number, since it uses as much as digits as its factorization.

12531809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 12531809 is about 3540.0295196509. The cubic root of 12531809 is about 232.2761339982.

The spelling of 12531809 in words is "twelve million, five hundred thirty-one thousand, eight hundred nine".