Main Page | See live article | Alphabetical index For the year A.D. 53, see 53. Fifty-three (53, LIII) is the natural number following fifty-two and preceding fifty-four. Fifty-three is the 16th smallest prime number. The next is fifty-nine. Fifty-three is also the sum of five consecutive primes (5 + 7 + 11 + 13 + 17). Fifty-three is also: The atomic number of iodine. The code for international direct dial phone calls to Cuba. In the title of the 1912 movie North of Fifty Three, remade in 1917. The number of short poems in the book Rumi Birdsong by Jelaluddin Rumi. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.