189 (number)
# 189 (number)

189 (one hundred [and] eighty-nine) is the natural number following 188 and preceding 190.

## In mathematics

189 is a centered cube number and a heptagonal number. The centered cube numbers are the sums of two consecutive cubes, and 189 can be written as sum of two cubes in two ways: $4^3$ + $5^3$ and $6^3$ + $(−3)^3.$ The smallest number that can be written as the sum of two positive cubes in two ways is 1729.

There are 189 zeros among the decimal digits of the positive integers with at most three digits.

The largest prime number that can be represented in 256-bit arithmetic is the "ultra-useful prime" $2^{256}$ − 189, used in quasi-Monte Carlo methods and in some cryptographic systems.

