• 289 is the smallest number with distinct digits such that divided by any of its digits leaves the same nonzero remainder. There are 40 such numbers, the largest being 843697.
• 289 can be written using four 4's:
The square root of 289 is 17.
289 is nontrivially palindromic in base 4 and base 16.
289 is an esthetic number in base 16, because in such base its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 982 = 2 ⋅491.
It is a Duffinian number.
289 is an undulating number in base 16.
289 is a lucky number.
It is a plaindrome in base 10, base 14 and base 15.
It is a nialpdrome in base 8.
289 is a Friedman number, since it can be written as (9+8)^2, using all its digits and the basic arithmetic operations.
289 is the 17-th square number.
289 is the 9-th centered octagonal number.
It is an amenable number.
289 is an equidigital number, since it uses as much as digits as its factorization.
289 is an odious number, because the sum of its binary digits is odd.
The cubic root of 289 is about 6.6114890185.
Multiplying 289 by its product of digits (144), we get a triangular number (41616 = T288).
The spelling of 289 in words is "two hundred eighty-nine", and thus it is an aban number.