The number 30 is an integer that follows 29 and precedes 31. It is an even number and can be divided by 1, 2, 3, 5, 6, 10, 15, and 30 itself. In Roman numerals, it is represented as XXX. In mathematics, 30 is known as a composite number because it has divisors other than 1 and itself. It is also the sum of the first four positive integers, making it a triangular number. Additionally, 30 is significant in various cultures, often marking milestones such as turning 30 years old.