18444309 has 16 divisors (see below), whose sum is σ = 26861184. Its totient is φ = 11188800.

The previous prime is 18444289. The next prime is 18444323. The reversal of 18444309 is 90344481.

It is a happy number.

It is not a de Polignac number, because 18444309 - 2²⁰ = 17395733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18444309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18444329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 562 + ... + 6099.

It is an arithmetic number, because the mean of its divisors is an integer number (1678824).

Almost surely, 2^18444309 is an apocalyptic number.

It is an amenable number.

18444309 is a deficient number, since it is larger than the sum of its proper divisors (8416875).

18444309 is a wasteful number, since it uses less digits than its factorization.

18444309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6748.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 18444309 is about 4294.6838067546. The cubic root of 18444309 is about 264.2129680750.

The spelling of 18444309 in words is "eighteen million, four hundred forty-four thousand, three hundred nine".