18011803 has 4 divisors (see below), whose sum is σ = 18021240. Its totient is φ = 18002368.

The previous prime is 18011771. The next prime is 18011809. The reversal of 18011803 is 30811081.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18011803 - 2⁵ = 18011771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18011809) by changing a digit.

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, 733 + ... + 6046.

It is an arithmetic number, because the mean of its divisors is an integer number (4505310).

Almost surely, 2^18011803 is an apocalyptic number.

18011803 is a deficient number, since it is larger than the sum of its proper divisors (9437).

18011803 is an equidigital number, since it uses as much as digits as its factorization.

18011803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9436.

The product of its (nonzero) digits is 192, while the sum is 22.

The square root of 18011803 is about 4244.0314560568. The cubic root of 18011803 is about 262.1314095173.

Adding to 18011803 its reverse (30811081), we get a palindrome (48822884).

The spelling of 18011803 in words is "eighteen million, eleven thousand, eight hundred three".