289

Number
$289$ (two hundred and eighty-nine) is:


 * $17^2$


 * The $17$th square number after $1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256$:
 * $289 = 17 \times 17$


 * The $29$th powerful number after $1, 4, 8, 9, 16, 25, \ldots, 144, 169, 196, 200, 216, 225, 243, 256, 288$


 * The larger of the $2$nd pair of consecutive powerful numbers:
 * $288 = 2^5 \times 3^2$, $289 = 17^2$


 * The $54$th lucky number:
 * $1, 3, 7, 9, 13, 15, 21, \ldots, 237, 241, 259, 261, 267, 273, 283, 285, 289,\ldots$


 * The $6$th square lucky number:
 * $1, 9, 25, 49, 169, 289, \ldots$


 * The $15$th positive integer which cannot be expressed as the sum of a square and a prime:
 * $1, 10, 25, 34, 58, 64, 85, 91, 121, 130, 169, 196, 214, 226, 289, \ldots$