fortyfive

fortyfive is the natural number following forty-four and preceding forty-six. In the decimal system, it is written as 45. It is an odd number. In mathematics, forty-five is a composite number. Its prime factorization is 3 squared multiplied by 5 (3 x 3 x 5). It is a triangular number, meaning it can be represented as the sum of consecutive integers starting from 1, specifically 1 + 2 + 3 + ... + 9. It is also a pentagonal number.

The Roman numeral for forty-five is XLV. In base-10, forty-five is the sum of the digits 4 and 5, which equals 9. The number forty-five plays a role in various cultural contexts. For instance, in sports, a forty-five degree angle is often a significant measurement. In some music scales, there are forty-five degrees between certain notes. It is also a common age for various life milestones or celebrations in different societies. The word "forty-five" is derived from the Old English "fēowertig" (forty) and "fīf" (five).