16609 has 4 divisors (see below), whose sum is σ = 17604. Its totient is φ = 15616.

The previous prime is 16607. The next prime is 16619. The reversal of 16609 is 90661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90661 = 17 ⋅5333.

It can be written as a sum of positive squares in 2 ways, for example, as 14400 + 2209 = 120^2 + 47^2 .

It is a cyclic number.

It is not a de Polignac number, because 16609 - 2¹ = 16607 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 16609.

It is not an unprimeable number, because it can be changed into a prime (16603) 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, 472 + ... + 505.

It is an arithmetic number, because the mean of its divisors is an integer number (4401).

2¹⁶⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

16609 is a deficient number, since it is larger than the sum of its proper divisors (995).

16609 is an equidigital number, since it uses as much as digits as its factorization.

16609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 16609 is about 128.8759093081. The cubic root of 16609 is about 25.5141533630.

It can be divided in two parts, 16 and 609, that added together give a 4-th power (625 = 5⁴).

The spelling of 16609 in words is "sixteen thousand, six hundred nine".