Number 18

Interestingness: 12 · Rank #88 of 1000

Visual representations

Binary image (n×n bits)
Element Ar – Argon
Heptagonal · P7(3) = 18
23²
Prime factorization

Representations of 18

Greek numeral
ιηʹ
Sanskrit numeral
१८
Arabic numeral
١٨
Roman numeral
XVIII
Maya numeral
●●●
▃▃▃▃▃
▃▃▃▃▃
▃▃▃▃▃
Chinese numeral
十八
Hebrew numeral
חי
Egyptian numeral
𓎆
𓏹𓏹𓏹𓏹𓏹𓏹𓏹𓏹
Morse code
.-------..

18 in different numeral systems

Binary
10010
Base-3
200
Base-4
102
Base-5
33
Base-6
30
Base-7
24
Base-8
22
Duodecimal
16
Hex
12
Vigesimal
i
Base-24
i
Base-36
i
Negabinary
10110

Factorization

Prime factors: 2, 3
Divisors: 1, 2, 3, 6, 9, 18
Sum of divisors other than 18: 21
Product of prime factors: 18 = 2 × 3 × 3

Number-theory characteristics (7)

Heptagonal Evil number Lucas number Refactorable Even Composite Abundant

Base-10 digit properties (1)

These depend on the decimal representation of the number.

Harshad

Related primes

Number 18 prime
Prime number before 18
Prime number after 18