18 (number)
18 (eighteen) is a number. It comes between seventeen and nineteen, and is an even number. It is divisible by 1, 2, 3, 6, 9 and 18. In most countries it is the age of majority, age of consent, and voting age.
| ||||
|---|---|---|---|---|
| Cardinal | eighteen | |||
| Ordinal | 18th (eighteenth) | |||
| Factorization | 2 · 32 | |||
| Roman numeral | XVIII | |||
| Binary | 100102 | |||
| Ternary | 2003 | |||
| Quaternary | 1024 | |||
| Quinary | 335 | |||
| Senary | 306 | |||
| Octal | 228 | |||
| Duodecimal | 1612 | |||
| Hexadecimal | 1216 | |||
| Vigesimal | I20 | |||
| Base 36 | I36 | |||
In Roman numerals, 18 is written as XVIII.
The number 18 has many multiples such as: 36, 54, 72, 90, 108, and so on. The prime factorization of 18 is 3x3x2 in expanded form, and 2x3² in factored form.