Main Page | See live article | Alphabetical index One hundred three (also One hundred and three) (103, CIII) is the natural number following one hundred two and preceding one hundred four. It is the 27nd prime number. The previous prime is one hundred one, with which it comprises a twin prime. One hundred three is also: The atomic number of lawrencium, an actinide. This article is about the number. For the year AD 103, see 103. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.