18164309 has 4 divisors (see below), whose sum is σ = 18188940. Its totient is φ = 18139680.

The previous prime is 18164281. The next prime is 18164339. The reversal of 18164309 is 90346181.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5276209 + 12888100 = 2297^2 + 3590^2 .

It is a cyclic number.

It is not a de Polignac number, because 18164309 - 2⁸ = 18164053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18164339) 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 in 3 ways as a sum of consecutive naturals, for example, 11174 + ... + 12695.

It is an arithmetic number, because the mean of its divisors is an integer number (4547235).

Almost surely, 2^18164309 is an apocalyptic number.

It is an amenable number.

18164309 is a deficient number, since it is larger than the sum of its proper divisors (24631).

18164309 is an equidigital number, since it uses as much as digits as its factorization.

18164309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24630.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 18164309 is about 4261.9606990211. The cubic root of 18164309 is about 262.8691537827.

The spelling of 18164309 in words is "eighteen million, one hundred sixty-four thousand, three hundred nine".