585

585 is a natural number that follows 584 and precedes 586. In mathematics, it factors as 3^2 × 5 × 13 and is therefore a composite number. It is divisible by 9 and by 5, and can be expressed as 9 × 65. Its digit sum is 18, which relates to its divisibility by 9 and 3.

In numeral systems, 585 is written as DLXXXV in Roman numerals. In binary it is 1001001001, and in hexadecimal it is 0x249.

In jewelry, 585 denotes alloy fineness of 58.5% gold, equivalent to 14 karat gold. This stamp is commonly used on gold pieces in various markets to indicate the proportion of gold in the alloy, with the remaining 41.5% consisting of other metals.

In telecommunications, 585 is the North American area code assigned to a large portion of the Rochester, New York metropolitan area. Area codes are part of the dialing plan to route calls to geographic regions.

Historically, the year 585 BCE is notable for the recorded sighting of a solar eclipse that, according to ancient chronicles, contributed to a cessation of hostilities between Lydia and Media. The event has been cited in discussions of early astronomical dating, though the precision and interpretation of these ancient accounts are debated among scholars.