265 (number)

← 264 265 266 →
← 260 261 262 263 264 265 266 267 268 269 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred sixty-five
Ordinal	265th (two hundred sixty-fifth)
Factorization	5 × 53
Divisors	1, 5, 53, 265
Greek numeral	ΣΞΕ´
Roman numeral	CCLXV, cclxv
Binary	1000010012
Ternary	1002113
Senary	11216
Octal	4118
Duodecimal	1A112
Hexadecimal	10916

265 (two hundred [and] sixty-five) is the natural number following 264 and preceding 266.

In mathematics

• 265 is an odd composite number with two prime factors. ^[1]
• 265's sum of its proper divisors is 59. ^[2]
• 265 is the number of derangements possible with 6 digits. That means that it is equivalent to !6. ^[3]
• The number 265 is associated with the geometric shape known as the Vesica Piscis. This is shown by having 2 circles overlap in a way that the circumference of each circle touches the center of the other. Archimedes estimated that the ratio of the height of this shape to the width was 265:153 or approximately √3. ^[4]
• 265 is the 22nd Padovan number which is defined by the two equations P(0)=P(1)=P(2)=1 and P(n)=P(n-2)+P(n-3) similar to the Fibonacci sequence. ^[5]
• 265 is the 7th number to be the hypotenuse for two separate Pythagorean Triples. The other two values would be 23 and 264 or 96 and 247. ^[6]
• 265 is the sum of two sets of two perfect squares. Those being 11 and 12 or 16 and 3.
• 265 is palindromic in base 12 (1A1).

References

1. "Facts about the integer". mathworld.wolfram.com.
2. "Proper divisors of 265". numbermatics.com.
3. "Derangement sequence". mathworld.wolfram.com.
4. "Vescica Piscis". mathworld.wolfram.com.
5. "Padovan sequence". mathworld.wolfram.com.
6. "Pythagorean triples list" (PDF). aleph0.clarku.edu.