18045505 has 4 divisors (see below), whose sum is σ = 21654612. Its totient is φ = 14436400.

The previous prime is 18045491. The next prime is 18045541. The reversal of 18045505 is 50554081.

It is a Cunningham number, because it is equal to 4248²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50554081 = 4363 ⋅11587.

It can be written as a sum of positive squares in 2 ways, for example, as 6492304 + 11553201 = 2548^2 + 3399^2 .

It is not a de Polignac number, because 18045505 - 2⁵ = 18045473 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, 1804546 + ... + 1804555.

It is an arithmetic number, because the mean of its divisors is an integer number (5413653).

Almost surely, 2^18045505 is an apocalyptic number.

It is an amenable number.

18045505 is a deficient number, since it is larger than the sum of its proper divisors (3609107).

18045505 is an equidigital number, since it uses as much as digits as its factorization.

18045505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3609106.

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 18045505 is about 4248.0001177024. Note that the first 3 decimals coincide. The cubic root of 18045505 is about 262.2947995729.

Adding to 18045505 its reverse (50554081), we get a palindrome (68599586).

The spelling of 18045505 in words is "eighteen million, forty-five thousand, five hundred five".