28345 has 4 divisors (see below), whose sum is σ = 34020. Its totient is φ = 22672.

The previous prime is 28319. The next prime is 28349. The reversal of 28345 is 54382.

28345 is nontrivially palindromic in base 4.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54382 = 2 ⋅27191.

It can be written as a sum of positive squares in 2 ways, for example, as 8464 + 19881 = 92^2 + 141^2 .

It is a cyclic number.

It is not a de Polignac number, because 28345 - 2¹¹ = 26297 is a prime.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2830 + ... + 2839.

It is an arithmetic number, because the mean of its divisors is an integer number (8505).

2²⁸³⁴⁵ is an apocalyptic number.

It is an amenable number.

28345 is a deficient number, since it is larger than the sum of its proper divisors (5675).

28345 is an equidigital number, since it uses as much as digits as its factorization.

28345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5674.

The product of its digits is 960, while the sum is 22.

The square root of 28345 is about 168.3597339033. The cubic root of 28345 is about 30.4900980129.

It can be divided in two parts, 28 and 345, that added together give a palindrome (373).

The spelling of 28345 in words is "twenty-eight thousand, three hundred forty-five".