Divisors of the Positive Integer 18

1, 2, 3, 6, 9, 18

Sum of all the Divisors of 18, including itself

39

Sum of the Proper Divisors of 18

21

Properties of the number 18

The integer 18 is an even number.
The integer 18 is a Composite number.
21 is greater than 18, so 18 is an abundant number.

The number 18 as a Roman Numeral

XVIII

The number 18 in various Numeral Systems

Base Representation
2:10010
3:200
4:102
5:33
6:30
7:24
8:22
9:20
10:18
11:17
12:16
13:15
14:14
15:13
16:12
17:11
18:10
19:I
20:I
21:I
22:I
23:I
24:I
25:I
26:I
27:I
28:I
29:I
30:I
31:I
32:I
33:I
34:I
35:I
36:I