The number 400,000 is a whole number that comes after 399,999 and before 400,001. It is often used in various contexts, such as population counts, financial figures, or statistical data. For example, a city might have a population of 400,000 residents, indicating a sizable community. In terms of numerical representation, 400,000 can also be expressed in scientific notation as 4 x 10^5. This format is commonly used in mathematics and science to simplify large numbers. Additionally, 400,000 is significant in discussions about economics, demographics, and data analysis.