400000

400,000 is a natural number that follows 399,999 and precedes 400,001. In decimal notation it is a round figure equal to four hundred thousand, and it can be expressed as 4×10^5. Its prime factorization is 2^7 × 5^5, which also shows why it is a multiple of both 2 and 5. The number has 48 positive divisors.

In different numeral systems, 400,000 appears as follows: decimal 400000; hexadecimal 0x61A80; binary 1100001101010000000. In Roman numerals, 400,000 is typically represented as CD with a vinculum (a bar) over the letters to indicate multiplication by 1,000.

As a round decimal, 400,000 is commonly used as a counting target, budget figure, or threshold in statistics, planning, and reporting. It can serve as an approximation for large populations, production quotas, or capacity planning when exact figures are unnecessary or impractical.

Mathematical properties include its expression as a power-of-ten multiple and its factorization into a product of powers of 2 and 5. Its place in the sequence of natural numbers and its role as a base-10 round number make it a convenient reference point in numerical contexts.

See also: powers of ten, 2^7 × 5^5, 4×10^5, Roman numerals.