261 (number)

261 (two hundred [and] sixty-one) is the natural number following 260 and preceding 262. It has the prime factorization 3²·29.

← 260 261 262 →
← 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-one
Ordinal	261st (two hundred sixty-first)
Factorization	32 × 29
Divisors	1, 3, 9, 29, 87, 261
Greek numeral	ΣΞΑ´
Roman numeral	CCLXI, cclxi
Binary	1000001012
Ternary	1002003
Senary	11136
Octal	4058
Duodecimal	19912
Hexadecimal	10516

In Mathematics

There are six divisors of this number, the divisors being 1, 3, 9, 29, 87, and 261 itself.^[1] 261 is a deficient number, since 1 + 3 + 9 + 29 + 87 = 129 < 261.

261 is nonagonal number, ^[2] unique period in base 2, and the number of possible unfolded tesseract patterns.

261 is a lucky number, ^[3] as well as an odious number, meaning it has an odd number of 1's in its binary expansion, which is 100000101₂ (with 3 ones in it).^[4]