28668 has 12 divisors (see below), whose sum is σ = 66920. Its totient is φ = 9552.

The previous prime is 28663. The next prime is 28669. The reversal of 28668 is 86682.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661) 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, 1183 + ... + 1206.

2²⁸⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

28668 is an abundant number, since it is smaller than the sum of its proper divisors (38252).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33460).

28668 is a wasteful number, since it uses less digits than its factorization.

28668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2396 (or 2394 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 28668 is about 169.3162721064. The cubic root of 28668 is about 30.6054755463.

It can be divided in two parts, 28 and 668, that added together give a palindrome (696).

The spelling of 28668 in words is "twenty-eight thousand, six hundred sixty-eight".