4

CardinalfourOrdinal4th
(fourth)Numeral systemquaternaryFactorization2Divisors1, 2, 4Greek numeralΔ´Roman numeralGreekprefixLatinprefix/Binary100₂Ternary11₃Senary4₆Octal4₈Duodecimal4₁₂Hexadecimal4₁₆ArmenianԴArabic, Kurdish٤Persian, Sindhi۴Shahmukhi, Urdu۴Ge'ez፬Bengali, Assamese৪Chinese numeral四，亖，肆Devanagari४Santali᱔Telugu౪Malayalam൪Tamil௪HebrewדKhmer៤Thai๔Kannada೪Burmese၄Babylonian numeral𒐘Egyptian hieroglyph, Chinese counting rod||||Maya numerals••••Morse code.... _

4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures.