18661103 has 4 divisors (see below), whose sum is σ = 18699000. Its totient is φ = 18623208.

The previous prime is 18661099. The next prime is 18661129. The reversal of 18661103 is 30116681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18661103 - 2² = 18661099 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 (18661133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18200 + ... + 19197.

It is an arithmetic number, because the mean of its divisors is an integer number (4674750).

Almost surely, 2^18661103 is an apocalyptic number.

18661103 is a deficient number, since it is larger than the sum of its proper divisors (37897).

18661103 is an equidigital number, since it uses as much as digits as its factorization.

18661103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37896.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18661103 is about 4319.8498816510. The cubic root of 18661103 is about 265.2441229696.

Adding to 18661103 its reverse (30116681), we get a palindrome (48777784).

The spelling of 18661103 in words is "eighteen million, six hundred sixty-one thousand, one hundred three".