3615

3615 is a positive integer with several notable mathematical and historical aspects. In number theory, it factors as 3 × 5 × 241, making it a composite number. The digit sum is 15, so it is divisible by 3, and the last digit is 5, so it is divisible by 5; indeed 3615 = 15 × 241. Its square root is about 60.1, and it is not a perfect square or cube.

In numeral representations, 3615 equals 0xE1F in hexadecimal and 0o7047 in octal. In binary it is 111000011111. In Roman numerals it is written as MMMDCXV (3000 + 600 + 15).

Historically, the number 3615 is notable in the context of telecommunications in France. The four-digit sequence 3615 was used as a general access prefix on the Minitel network, which operated from the late 1980s into the 1990s. It served as a gateway for accessing a wide range of paid services hosted on the network, reflecting an early model of online services before the commercial internet era.

As a four-digit numeric identifier, 3615 also appears in puzzles, problems, and trivia as an example of a small composite number with simple prime factors. Its various base representations and historical use provide a compact illustration of how a single number can have multiple mathematical properties and cultural associations.