28609 has 8 divisors (see below), whose sum is σ = 33728. Its totient is φ = 23760.

The previous prime is 28607. The next prime is 28619. The reversal of 28609 is 90682.

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

It is a cyclic number.

It is not a de Polignac number, because 28609 - 2¹ = 28607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394 + ... + 460.

It is an arithmetic number, because the mean of its divisors is an integer number (4216).

2²⁸⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

28609 is a deficient number, since it is larger than the sum of its proper divisors (5119).

28609 is an equidigital number, since it uses as much as digits as its factorization.

28609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 28609 is about 169.1419522177. The cubic root of 28609 is about 30.5844653232.

The spelling of 28609 in words is "twenty-eight thousand, six hundred nine".