18005305 has 4 divisors (see below), whose sum is σ = 21606372. Its totient is φ = 14404240.

The previous prime is 18005291. The next prime is 18005333. The reversal of 18005305 is 50350081.

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 5253264 + 12752041 = 2292^2 + 3571^2 .

It is not a de Polignac number, because 18005305 - 2⁷ = 18005177 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

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, 1800526 + ... + 1800535.

It is an arithmetic number, because the mean of its divisors is an integer number (5401593).

Almost surely, 2^18005305 is an apocalyptic number.

It is an amenable number.

18005305 is a deficient number, since it is larger than the sum of its proper divisors (3601067).

18005305 is an equidigital number, since it uses as much as digits as its factorization.

18005305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3601066.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 18005305 is about 4243.2658413067. The cubic root of 18005305 is about 262.0998832495.

Adding to 18005305 its reverse (50350081), we get a palindrome (68355386).

The spelling of 18005305 in words is "eighteen million, five thousand, three hundred five".