16818665 has 4 divisors (see below), whose sum is σ = 20182404. Its totient is φ = 13454928.

The previous prime is 16818653. The next prime is 16818671. The reversal of 16818665 is 56681861.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12988816 + 3829849 = 3604^2 + 1957^2 .

It is a cyclic number.

It is not a de Polignac number, because 16818665 - 2¹⁶ = 16753129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1681862 + ... + 1681871.

It is an arithmetic number, because the mean of its divisors is an integer number (5045601).

Almost surely, 2^16818665 is an apocalyptic number.

It is an amenable number.

16818665 is a deficient number, since it is larger than the sum of its proper divisors (3363739).

16818665 is an equidigital number, since it uses as much as digits as its factorization.

16818665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3363738.

The product of its digits is 69120, while the sum is 41.

The square root of 16818665 is about 4101.0565711777. The cubic root of 16818665 is about 256.2106471394.

The spelling of 16818665 in words is "sixteen million, eight hundred eighteen thousand, six hundred sixty-five".