18361663 has 4 divisors (see below), whose sum is σ = 18370240. Its totient is φ = 18353088.

The previous prime is 18361661. The next prime is 18361667. The reversal of 18361663 is 36616381.

It is a happy number.

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 18361663 - 2¹ = 18361661 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 (18361661) 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, 1906 + ... + 6352.

It is an arithmetic number, because the mean of its divisors is an integer number (4592560).

Almost surely, 2^18361663 is an apocalyptic number.

18361663 is a deficient number, since it is larger than the sum of its proper divisors (8577).

18361663 is an equidigital number, since it uses as much as digits as its factorization.

18361663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8576.

The product of its digits is 15552, while the sum is 34.

The square root of 18361663 is about 4285.0511082133. The cubic root of 18361663 is about 263.8177451519.

The spelling of 18361663 in words is "eighteen million, three hundred sixty-one thousand, six hundred sixty-three".