23640209 has 2 divisors, whose sum is σ = 23640210. Its totient is φ = 23640208.

The previous prime is 23640203. The next prime is 23640233. The reversal of 23640209 is 90204632.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23309584 + 330625 = 4828^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 23640209 - 2⁴ = 23640193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (23640203) 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, 11820104 + 11820105.

It is an arithmetic number, because the mean of its divisors is an integer number (11820105).

Almost surely, 2^23640209 is an apocalyptic number.

It is an amenable number.

23640209 is a deficient number, since it is larger than the sum of its proper divisors (1).

23640209 is an equidigital number, since it uses as much as digits as its factorization.

23640209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 23640209 is about 4862.1198051879. The cubic root of 23640209 is about 287.0012383246.

The spelling of 23640209 in words is "twenty-three million, six hundred forty thousand, two hundred nine".