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28489 = 31919
BaseRepresentation
bin110111101001001
31110002011
412331021
51402424
6335521
7146026
oct67511
943064
1028489
111a44a
12145a1
13cc76
14a54d
158694
hex6f49

28489 has 4 divisors (see below), whose sum is σ = 29440. Its totient is φ = 27540.

The previous prime is 28477. The next prime is 28493. The reversal of 28489 is 98482.

28489 divided by its sum of digits (31) gives a palindrome (919).

It can be divided in two parts, 284 and 89, that added together give a palindrome (373).

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 28489 - 213 = 20297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 919 = 28489 / (2 + 8 + 4 + 8 + 9).

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 28489.

It is not an unprimeable number, because it can be changed into a prime (28409) 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, 429 + ... + 490.

It is an arithmetic number, because the mean of its divisors is an integer number (7360).

228489 is an apocalyptic number.

It is an amenable number.

28489 is a deficient number, since it is larger than the sum of its proper divisors (951).

28489 is an equidigital number, since it uses as much as digits as its factorization.

28489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950.

The product of its digits is 4608, while the sum is 31.

The square root of 28489 is about 168.7868478289. The cubic root of 28489 is about 30.5416433759.

The spelling of 28489 in words is "twenty-eight thousand, four hundred eighty-nine".

Divisors: 1 31 919 28489