189 is:

• an odd number
• a centered cube number[
• a composite number
• a deficient number, as 131 is less than 189
• a heptagonal number
• a lucky number
• an Ulam number
• a 64-gonal number
• a Kaprekar constant in base 2
• palindromic in bases 2 (10111101), 20 (99), 26 (7726) and 62 (33).
• a Harshad number in bases 3, 4, 5, 6, 7, 11, 13, 15 (and 28 other bases).
• the sum of the sums of the divisors of the first 15 positive integers.