18163903 has 4 divisors (see below), whose sum is σ = 18173008. Its totient is φ = 18154800.

The previous prime is 18163891. The next prime is 18163907. The reversal of 18163903 is 30936181.

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 18163903 - 2¹⁷ = 18032831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18163907) 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, 123 + ... + 6028.

It is an arithmetic number, because the mean of its divisors is an integer number (4543252).

Almost surely, 2^18163903 is an apocalyptic number.

18163903 is a deficient number, since it is larger than the sum of its proper divisors (9105).

18163903 is an equidigital number, since it uses as much as digits as its factorization.

18163903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9104.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 18163903 is about 4261.9130680951. The cubic root of 18163903 is about 262.8671952593.

The spelling of 18163903 in words is "eighteen million, one hundred sixty-three thousand, nine hundred three".