217 (number)

← 216 218 → 217
← 200 210 220 230 240 250 260 270 280 290 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred [and] seventeen
Ordinal	217th (two hundred [and] seventeenth)
Factorization	$7 \cdot 31$
Roman numeral	CCXVII
Binary	110110012
Octal	3318
Duodecimal	16112
Hexadecimal	D916

217 is the natural number following 216 and preceding 218.

Here are the representations of 217 in other numeral systems:

217 base	representation of 217
2	11011001
8	331
16	D9

217 is a centered hexagonal number, a 12-gonal number, a centered 36-gonal number, and a Blum integer. It is both the sum of two positive cubes and the difference of two positive consecutive cubes in exactly one way: $217 = 6^3 + 1^3 = 9^3 - 8^3$. When written in binary, it is a non-repetitive Kaprekar number.

See also

• The year 217
• 217 is the area code for central Illinois
• In Stephen King's novel "The Shining", room 217 plays a central part of the story as it is haunted.
• When read upside-down on a digital clock, it appears to say "LIZ"