16689 has 4 divisors (see below), whose sum is σ = 22256. Its totient is φ = 11124.

The previous prime is 16673. The next prime is 16691. The reversal of 16689 is 98661.

16689 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 98661 = 3 ⋅32887.

It is not a de Polignac number, because 16689 - 2⁴ = 16673 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 10 and base 13.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (16619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2779 + ... + 2784.

It is an arithmetic number, because the mean of its divisors is an integer number (5564).

2¹⁶⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

16689 is a deficient number, since it is larger than the sum of its proper divisors (5567).

16689 is an equidigital number, since it uses as much as digits as its factorization.

16689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5566.

The product of its digits is 2592, while the sum is 30.

The square root of 16689 is about 129.1859125447. The cubic root of 16689 is about 25.5550521500. Note that the first 3 decimals are identical.

The spelling of 16689 in words is "sixteen thousand, six hundred eighty-nine".