28008 has 24 divisors (see below), whose sum is σ = 76050. Its totient is φ = 9312.
The previous prime is 28001. The next prime is 28019. The reversal of 28008 is 80082.
28008 is nontrivially palindromic in base 7.
It can be written as a sum of positive squares in only one way, i.e., 26244 + 1764 = 162^2 + 42^2 .
It is a tau number, because it is divible by the number of its divisors (24).
It is a Harshad number since it is a multiple of its sum of digits (18).
It is a nialpdrome in base 8 and base 13.
It is not an unprimeable number, because it can be changed into a prime (28001) by changing a digit.
28008 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 123 + ... + 266.
228008 is an apocalyptic number.
It is an amenable number.
28008 is an abundant number, since it is smaller than the sum of its proper divisors (48042).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
28008 is a wasteful number, since it uses less digits than its factorization.
28008 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 401 (or 394 counting only the distinct ones).
The product of its (nonzero) digits is 128, while the sum is 18.
The square root of 28008 is about 167.3559081718. The cubic root of 28008 is about 30.3687814329.
The spelling of 28008 in words is "twenty-eight thousand, eight".
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