407

407 is an integer that appears in several different contexts. In mathematics, 407 is a semiprime, the product of two primes: 11 and 37. It is an odd composite number, and in Roman numerals it is written as CDVII.

In computing, 407 is the HTTP status code Proxy Authentication Required. It indicates that the client must first authenticate with the proxy server before the request can be fulfilled.

In telecommunications, area code 407 covers central Florida, including the city of Orlando. It overlays with the 321 area code, serving the same general region.

In European food labeling, E407 refers to carrageenan, a gelling and thickening agent derived from red seaweed. Carrageenan is used to stabilize and improve texture in a variety of dairy, meat, and plant-based products.

As a calendar year, 407 can denote a year in the common era (CE) or before it (BCE) in historical dating. It sits in the early fifth century and is referenced in chronicles and scholarly timelines documenting the late Roman Empire and related migrations.

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