395

395 is a natural number that follows 394 and precedes 396. In mathematics, it is a semiprime, since it factors into the product of two prime numbers: 5 and 79. As a result, it is composite and has exactly four divisors: 1, 5, 79, and 395.

Representations of the number include Roman numerals, binary, and hexadecimal. In Roman numerals it is CCCXCV; in binary it is 110001011; in hexadecimal, it is 0x18B; and in scientific notation it is 3.95 × 10^2.

Historical year 395 CE is notable in the context of the Roman Empire. Theodosius I died in 395, and the empire was permanently divided into Eastern and Western halves, ruled by Arcadius and Honorius, respectively. The Western and Eastern Roman Empires persisted for several centuries, with the West collapsing in the late 5th century and the East continuing as the Byzantine Empire until 1453.

In transportation, the number 395 is used for highway designations in multiple countries. Notably, there is U.S. Route 395, a major north–south highway in the western United States, and California State Route 395, which carries traffic across parts of eastern California. These designations reflect a common practice of assigning numerical identifiers to regional road networks.