# 216 (number)

 ← 215 216 217 →
Cardinaltwo hundred sixteen
Ordinal216th
(two hundred and sixteenth)
Factorization23× 33
Divisors1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 108, 216
Roman numeralCCXVI
Binary110110002
Ternary220003
Quaternary31204
Quinary13315
Senary10006
Octal3308
Duodecimal16012
VigesimalAG20
Base 366036

 ← 215 216 217 →
Cardinaltwo hundred sixteen
Ordinal216th
(two hundred and sixteenth)
Factorization23× 33
Divisors1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 108, 216
Roman numeralCCXVI
Binary110110002
Ternary220003
Quaternary31204
Quinary13315
Senary10006
Octal3308
Duodecimal16012
VigesimalAG20
Base 366036

216 is a natural number.

Since $216 = 3^3 + 4^3 + 5^3 = 6^3$, it is the smallest cube that's also the sum of three cubes (Plato was among the first to notice this, and mentioned it in Book VIII of Republic). It is also the sum of a twin prime (107 + 109). But since there is no way to express it as the sum of the proper divisors of any other integer, it is an untouchable number.

This multiplicative magic square

$\begin{pmatrix} 2 & 9 & 12\\ 36 & 6 & 1\\ 3 & 4 & 18 \end{pmatrix}$

has magic constant 216.

In base 10, it is a Harshad number.

There are 216 fixed hexominoes, the polyominoes made from 6 squares.

216 is a Friedman number.