12421009 has 2 divisors, whose sum is σ = 12421010. Its totient is φ = 12421008.

The previous prime is 12421007. The next prime is 12421021. The reversal of 12421009 is 90012421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11370384 + 1050625 = 3372^2 + 1025^2 .

It is a cyclic number.

It is not a de Polignac number, because 12421009 - 2¹ = 12421007 is a prime.

Together with 12421007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12421007) 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, 6210504 + 6210505.

It is an arithmetic number, because the mean of its divisors is an integer number (6210505).

Almost surely, 2^12421009 is an apocalyptic number.

It is an amenable number.

12421009 is a deficient number, since it is larger than the sum of its proper divisors (1).

12421009 is an equidigital number, since it uses as much as digits as its factorization.

12421009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 12421009 is about 3524.3451874072. The cubic root of 12421009 is about 231.5895499813.

The spelling of 12421009 in words is "twelve million, four hundred twenty-one thousand, nine".