16663809 has 4 divisors (see below), whose sum is σ = 22218416. Its totient is φ = 11109204.

The previous prime is 16663793. The next prime is 16663819. The reversal of 16663809 is 90836661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16663809 - 2⁴ = 16663793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16663819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2777299 + ... + 2777304.

It is an arithmetic number, because the mean of its divisors is an integer number (5554604).

Almost surely, 2^16663809 is an apocalyptic number.

It is an amenable number.

16663809 is a deficient number, since it is larger than the sum of its proper divisors (5554607).

16663809 is an equidigital number, since it uses as much as digits as its factorization.

16663809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5554606.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 16663809 is about 4082.1328983756. The cubic root of 16663809 is about 255.4218775839.

The spelling of 16663809 in words is "sixteen million, six hundred sixty-three thousand, eight hundred nine".