261 (number)
| ||||
|---|---|---|---|---|
| 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 | |||
261 (two hundred [and] sixty-one) is the natural number following 260 and preceding 262.
In Mathematics
[edit]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]
References
[edit]- ^ "Facts about the number 261". Numbermatics - the number explorer. Retrieved 2017-03-20.
- ^ Sloane, N. J. A. (ed.). "Sequence A001106 (nonagonal number)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A000959 (lucky number)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Number Gossip: 261". www.numbergossip.com. Retrieved 2017-03-20.