12491009 has 2 divisors, whose sum is σ = 12491010. Its totient is φ = 12491008.

The previous prime is 12490997. The next prime is 12491023. The reversal of 12491009 is 90019421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11730625 + 760384 = 3425^2 + 872^2 .

It is a cyclic number.

It is not a de Polignac number, because 12491009 - 2⁴ = 12490993 is a prime.

It is not a weakly prime, because it can be changed into another prime (12491029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6245504 + 6245505.

It is an arithmetic number, because the mean of its divisors is an integer number (6245505).

Almost surely, 2^12491009 is an apocalyptic number.

It is an amenable number.

12491009 is a deficient number, since it is larger than the sum of its proper divisors (1).

12491009 is an equidigital number, since it uses as much as digits as its factorization.

12491009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 12491009 is about 3534.2621577919. The cubic root of 12491009 is about 232.0237849673.

The spelling of 12491009 in words is "twelve million, four hundred ninety-one thousand, nine".