## Composite number |

A **composite number** is a ^{[1]}^{[2]} Every positive integer is composite, ^{[3]}^{[4]}

For example, the integer

The composite numbers up to 150 are

- 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 128, 129, 130, 132, 133, 134, 135, 136, 138, 140, 141, 142, 143, 144, 145, 146, 147, 148, 150. (sequence A002808 in the
OEIS )

Every composite number can be written as the product of two or more (not necessarily distinct) primes.^{[5]} For example, the composite number ^{3} × 3^{2} × 5; furthermore, this representation is unique up to the order of the factors. This fact is called the ^{[6]}^{[7]}^{[8]}^{[9]}

There are several known

One way to classify composite numbers is by counting the number of prime factors. A composite number with two prime factors is a

(where μ is the *x* is half the total of prime factors), while for the former

However, for prime numbers, the function also returns −1 and . For a number *n* with one or more repeated prime factors,

- .
^{[10]}

If *all* the prime factors of a number are repeated it is called a *none* of its prime factors are repeated, it is called

For example, ^{3} × 3^{2}, all the prime factors are repeated, so 72 is a powerful number.

Another way to classify composite numbers is by counting the number of divisors. All composite numbers have at least three divisors. In the case of squares of primes, those divisors are . A number *n* that has more divisors than any *x* < *n* is a

Composite numbers have also been called "rectangular numbers", but that name can also refer to the

Yet another way to classify composite numbers is to determine whether all prime factors are either all below or all above some fixed (prime) number. Such numbers are called

Other Languages

العربية: عدد غير أولي

azərbaycanca: Mürəkkəb ədəd

Bân-lâm-gú: Ha̍p-sêng-sò͘

беларуская: Састаўны лік

български: Съставно число

català: Nombre compost

čeština: Složené číslo

dansk: Sammensat tal

Deutsch: Zusammengesetzte Zahl

eesti: Kordarv

Ελληνικά: Σύνθετος αριθμός

español: Número compuesto

Esperanto: Komponita nombro

euskara: Zenbaki konposatu

فارسی: اعداد مرکب

français: Nombre composé

galego: Número composto

한국어: 합성수

հայերեն: Բաղադրյալ թիվ

hrvatski: Složeni broj

Bahasa Indonesia: Bilangan komposit

italiano: Numero composto

עברית: מספר פריק

Kiswahili: Namba kivunge

Latina: Numerus compositus

latviešu: Salikts skaitlis

lietuvių: Sudėtinis skaičius

magyar: Összetett számok

മലയാളം: ഭാജ്യ സംഖ്യകൾ

Bahasa Melayu: Nombor gubahan

монгол: Зохиомол тоо

Nederlands: Samengesteld getal

日本語: 合成数

norsk: Sammensatt tall

norsk nynorsk: Samansett tal

ଓଡ଼ିଆ: ଯୌଗିକ ସଂଖ୍ୟା

polski: Liczba złożona

português: Número composto

română: Număr compus

русский: Составное число

Scots: Composite nummer

Simple English: Composite number

slovenčina: Zložené číslo

slovenščina: Sestavljeno število

ślůnski: Skuplowano nůmera

српски / srpski: Сложен број

suomi: Yhdistetty luku

svenska: Sammansatt tal

தமிழ்: பகு எண்

తెలుగు: సంయుక్త సంఖ్య

ไทย: จำนวนประกอบ

Türkçe: Bileşik sayı

українська: Складене число

اردو: مرکب عدد

Tiếng Việt: Hợp số

文言: 合數

ייִדיש: צוזאמענגעזעצטע צאל

粵語: 合成數

中文: 合数