18005663 has 4 divisors (see below), whose sum is σ = 19390728. Its totient is φ = 16620600.

The previous prime is 18005657. The next prime is 18005681. The reversal of 18005663 is 36650081.

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 18005663 - 2¹⁰ = 18004639 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 (18005623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 692513 + ... + 692538.

It is an arithmetic number, because the mean of its divisors is an integer number (4847682).

Almost surely, 2^18005663 is an apocalyptic number.

18005663 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18005663 is a deficient number, since it is larger than the sum of its proper divisors (1385065).

18005663 is a wasteful number, since it uses less digits than its factorization.

18005663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385064.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 18005663 is about 4243.3080255857. The cubic root of 18005663 is about 262.1016203512.

The spelling of 18005663 in words is "eighteen million, five thousand, six hundred sixty-three".