53 (number)
From Halbeeg, the open encyclopedia · Af-Soomaali
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53 is a natural number that lies between 52 and 54. It is written in standard Arabic numerals and is used in counting, classification, and measurement.
The most significant mathematical property of 53 is that it is a prime number, meaning only 1 and 53 divide it evenly. It is the 16th prime number, counting from 2.
Mathematical properties
53 is an odd number, since it is not divisible by 2. The sum of its digits is 5 + 3 = 8. When 53 is divided by smaller numbers, there is always a remainder: for example, 53 = (10 × 5) + 3. Its square is 2,809.
53 is also an isolated prime when viewed on the number line of primes, since the next prime is 59 and the previous is 47. Therefore, 53 is not part of a pair of twin primes, as 51 (3 × 17) and 55 (5 × 11) are both composite.
Other numeral systems
In binary (base 2), 53 is written as 110101. In hexadecimal (base 16), it is 35. In Roman numerals, it is written as LIII.
General usage
Like other numbers, 53 is used symbolically in many contexts: in history (the year 53), in road and country numbering systems, as Cuba's international telephone country code, and in sports jersey numbers. Such usage is based on social convention rather than on any mathematical property inherent in the number.