Eighteen (18) is a positive integer one more than 17 and one less than 19.
18 is an abundant composite number. Its factorization is 2*3^2. The previous abundant number is 12 and the next is 20.
18 is the sixth Lucas number, cetween 11 and 29.
18 is known for being the most common age at which you are considered an adult.
In googology Edit
In Greek-based number-naming systems, is associated with prefix "octadeka-", and with prefix "octodec-" in Latin systems.
Sbiis Saibian calls the number octaxis, and it's equal to 10+8 using the addition.
Cultural significance Edit
Since it is also the age of majority in most countries, it is associated with adult-only media. It is one of few non-single-digit numbers that has its own emoji: 🔞