261 (two hundred [and] sixty-one) is the natural number following 260 and preceding 262.
There are six divisors of this number, the divisors being , , , , , and 261 itself. 261 is a deficient number, since
261 is nonagonal number, unique period in base 2, and the number of possible unfolded tesseract patterns.
261 is a lucky number, as well as an odious number, meaning it has an odd number of 1's in its binary expansion, which is (with 3 ones in it).