4 (number)

This page is about the number 4. For the year, see 4

The number four is a number and a numeral. It comes after the number three, and before the number five. In Roman numerals, it is IV.

← 3 4 5 →
-1 0 1 2 3 4 5 6 7 8 9 → List of numbers — Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	four
Ordinal	4th (fourth)
Numeral system	quaternary
Factorization	22
Divisors	1, 2, 4
Greek numeral	Δ´
Roman numeral	IV
Roman numeral (unicode)	Ⅳ, ⅳ
Greek prefix	tetra-
Latin prefix	quadri-/quadr-
Binary	1002
Ternary	113
Quaternary	104
Quinary	45
Senary	46
Octal	48
Duodecimal	412
Hexadecimal	416
Vigesimal	420
Base 36	436
Greek	δ (or Δ)
Arabic	٤,4
Persian	۴
Urdu
Ge'ez	፬
Bengali	৪
Chinese numeral	四，亖，肆
Korean	넷,사
Devanagari	४
Telugu	౪
Malayalam	൪
Tamil	௪
Hebrew	ארבע (Arba, pronounced AR-bah) or ד (Dalet, 4th letter of the Hebrew alphabet)
Khmer	៤
Thai	๔
Kannada	४

Pronunciation of the number 4

Mathematics

In mathematics, the number four is an even number and the smallest composite number. Four is also the second square number after one. A small minority of people have four fingers on each hand and four toes on each foot.^[source?] Four squared is 16, and four doubled is 8.

In geometry, quadrilaterals or tetragons are a kind of shapes called polygons have four sides and vertices, to which squares are quadrilaterals with sides of same length and vertices of the same wideness.