79 (number)
From Halbeeg, the open encyclopedia · Af-Soomaali
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79 is a natural number that follows 78 and precedes 80. It is among the positive integers and is written in Arabic numerals as '79'. In Roman numerals it is denoted LXXIX.
79 is a prime number, meaning it cannot be divided by any number greater than 1 and less than itself. Its only divisors are 1 and 79. It is the 22nd prime number.
Mathematical properties
The sum of its digits is 7 + 9 = 16. 79 is an odd number and cannot be divided by 2. It is also a Chen prime and one of the circular primes, since both 79 and 97 are prime.
In binary notation it is 1001111, in hexadecimal it is 4F, and in octal it is 117.
Other uses
In chemistry, 79 is the atomic number of gold (Au), meaning the atom has 79 protons. In history, 79 refers to the year 79 AD in the common era, in the first century.