18016805 has 4 divisors (see below), whose sum is σ = 21620172. Its totient is φ = 14413440.

The previous prime is 18016799. The next prime is 18016829. The reversal of 18016805 is 50861081.

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 9449476 + 8567329 = 3074^2 + 2927^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18016805 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 1801676 + ... + 1801685.

It is an arithmetic number, because the mean of its divisors is an integer number (5405043).

Almost surely, 2^18016805 is an apocalyptic number.

It is an amenable number.

18016805 is a deficient number, since it is larger than the sum of its proper divisors (3603367).

18016805 is an equidigital number, since it uses as much as digits as its factorization.

18016805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3603366.

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 18016805 is about 4244.6207133265. The cubic root of 18016805 is about 262.1556724956.

Adding to 18016805 its reverse (50861081), we get a palindrome (68877886).

The spelling of 18016805 in words is "eighteen million, sixteen thousand, eight hundred five".