23218909 has 4 divisors (see below), whose sum is σ = 26535904. Its totient is φ = 19901916.

The previous prime is 23218883. The next prime is 23218913. The reversal of 23218909 is 90981232.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 23218909 - 2⁹ = 23218397 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23218939) 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 in 3 ways as a sum of consecutive naturals, for example, 1658487 + ... + 1658500.

It is an arithmetic number, because the mean of its divisors is an integer number (6633976).

Almost surely, 2^23218909 is an apocalyptic number.

It is an amenable number.

23218909 is a deficient number, since it is larger than the sum of its proper divisors (3316995).

23218909 is an equidigital number, since it uses as much as digits as its factorization.

23218909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3316994.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 23218909 is about 4818.6003154443. The cubic root of 23218909 is about 285.2860941621.

The spelling of 23218909 in words is "twenty-three million, two hundred eighteen thousand, nine hundred nine".