Number 30, also known as thirty, is a natural number that serves as the integer between 29 and 31. It is a cardinal number, representing三十 in the Roman numeral system. In mathematics, 30 holds several interesting properties and has been the subject of various mathematical inquiries. It is an even number and a composite number, as it can be divided by two, three, and five, the prime factors of 30. This makes it a regular number and the smallest sphenic number, meaning it can be expressed in the form where r is a prime number greater than 3. Additionally, 30 has an aliquot sum of 42, the second sphenic number, and is a semiperfect number due to the relationship between its proper divisors.
In Science, the原子序数为30的锌元素是其代表符号，属于过渡金属。在天文学领域，一颗编号为30的星体是位于小熊座的双星系统的一部分。
When it comes to music, 30 has a rich history and is the title of multiple studio albums by renowned artists. For instance, the Harry Connick Jr. album titled 30 and Adele's 30 are both popular works in the music industry. Moreover, 30 was an album released by Laurent Garnier in 1997. Other artists who have released albums titled 30 include James Yorkston, Jerusalem, Modern Talking, and Trio da Paz.
The number 30 is also frequently used in other fields, with one of its most prominent uses being a traditional marker for the end of a story or article, especially when submitting stories toeditors at publications. This practice is rooted in the 92 Code of telegraphic shorthand during the American Civil War era, which used the number to signify the end of a transmission. Over time, it has become a standard method for editors to indicate theof a piece they are working on.
Furthermore, 30 (film), released in 1959, is a classic film also known as Deadline Midnight. Additionally, the television series episode Law & Order: Criminal Intent, which aired in 2002, contains the element of the number 30. As a result, many people are familiar with 30 as a narrative element, often associated with theof a narrative within the arts and entertainment industries., number 30 is a diverse mathematical concept that pops up in various fields and disciplines. From its mathematical properties to its musical and other historical contexts, 30 is a number that has withstood the test of time. It is a number that has marked milestones in science, music, literature, and journalism, and remains a reliable and versatile tool for communication and commerce alike.
