18318305 has 4 divisors (see below), whose sum is σ = 21981972. Its totient is φ = 14654640.

The previous prime is 18318277. The next prime is 18318329. The reversal of 18318305 is 50381381.

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 6974881 + 11343424 = 2641^2 + 3368^2 .

It is not a de Polignac number, because 18318305 - 2⁸ = 18318049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1831826 + ... + 1831835.

It is an arithmetic number, because the mean of its divisors is an integer number (5495493).

Almost surely, 2^18318305 is an apocalyptic number.

It is an amenable number.

18318305 is a deficient number, since it is larger than the sum of its proper divisors (3663667).

18318305 is an equidigital number, since it uses as much as digits as its factorization.

18318305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663666.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 18318305 is about 4279.9889018548. The cubic root of 18318305 is about 263.6099276451.

Adding to 18318305 its reverse (50381381), we get a palindrome (68699686).

The spelling of 18318305 in words is "eighteen million, three hundred eighteen thousand, three hundred five".