18006665 has 8 divisors (see below), whose sum is σ = 21912768. Its totient is φ = 14202160.

The previous prime is 18006649. The next prime is 18006673. The reversal of 18006665 is 56660081.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18006665 - 2⁴ = 18006649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25007 + ... + 25716.

It is an arithmetic number, because the mean of its divisors is an integer number (2739096).

Almost surely, 2^18006665 is an apocalyptic number.

It is an amenable number.

18006665 is a deficient number, since it is larger than the sum of its proper divisors (3906103).

18006665 is an equidigital number, since it uses as much as digits as its factorization.

18006665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50799.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 18006665 is about 4243.4260922043. The cubic root of 18006665 is about 262.1064821726.

The spelling of 18006665 in words is "eighteen million, six thousand, six hundred sixty-five".