*** Welcome to piglix ***

10 (number)

← 9 10 11 →
Cardinal ten
Ordinal 10th
Numeral system decimal
Factorization 2 × 5
Divisors 1, 2, 5, 10
Roman numeral X
Roman numeral (unicode) X, x
Greek prefix /
Latin prefix
Binary 10102
Ternary 1013
Quaternary 224
Quinary 205
Senary 146
Octal 128
Duodecimal A12
Hexadecimal A16
Vigesimal A20
Base 36 A36
Chinese numeral 十,拾
Hebrew י (Yod)
Khmer ១០
Thai ๑๐
Devanāgarī १०
Bengali ১০
Arabic & Kurdish ١٠

10 (ten Listeni/ˈtɛn/) is an even natural number following 9 and preceding 11. Ten is the base of the decimal numeral system, by far the most common system of denoting numbers in both spoken and written language. The reason for the choice of ten is assumed to be that humans have ten fingers (digits).

Ten is a composite number, its proper divisors being 1, 2 and 5. Ten is the smallest noncototient, a number that cannot be expressed as the difference between any integer and the total number of coprimes below it.

Ten is the second discrete semiprime (2 × 5) and the second member of the (2 × q) discrete semiprime family. Ten has an aliquot sum σ(n) of 8 and is accordingly the first discrete semiprime to be in deficit. All subsequent discrete semiprimes are in deficit. The aliquot sequence for 10 comprises five members (10,8,7,1,0) with this number being the second composite member of the 7-aliquot tree.