18223809 has 4 divisors (see below), whose sum is σ = 24298416. Its totient is φ = 12149204.

The previous prime is 18223781. The next prime is 18223817. The reversal of 18223809 is 90832281.

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 18223809 - 2⁹ = 18223297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18223809.

It is not an unprimeable number, because it can be changed into a prime (18223409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3037299 + ... + 3037304.

It is an arithmetic number, because the mean of its divisors is an integer number (6074604).

Almost surely, 2^18223809 is an apocalyptic number.

It is an amenable number.

18223809 is a deficient number, since it is larger than the sum of its proper divisors (6074607).

18223809 is an equidigital number, since it uses as much as digits as its factorization.

18223809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6074606.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 18223809 is about 4268.9353473671. The cubic root of 18223809 is about 263.1558637956.

The spelling of 18223809 in words is "eighteen million, two hundred twenty-three thousand, eight hundred nine".