28189 has 4 divisors (see below), whose sum is σ = 32224. Its totient is φ = 24156.
The previous prime is 28183. The next prime is 28201. The reversal of 28189 is 98182.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 28189 - 23 = 28181 is a prime.
It is a Duffinian number.
28189 is a modest number, since divided by 189 gives 28 as remainder.
It is a nialpdrome in base 13 and base 15.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (28181) 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, 2007 + ... + 2020.
It is an arithmetic number, because the mean of its divisors is an integer number (8056).
228189 is an apocalyptic number.
It is an amenable number.
28189 is a deficient number, since it is larger than the sum of its proper divisors (4035).
28189 is an equidigital number, since it uses as much as digits as its factorization.
28189 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 4034.
The product of its digits is 1152, while the sum is 28.
The square root of 28189 is about 167.8958010196. The cubic root of 28189 is about 30.4340598172.
The spelling of 28189 in words is "twenty-eight thousand, one hundred eighty-nine".
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