706

Number
$706$ (seven hundred and six) is:
 * $2 \times 353$


 * The $23$rd positive integer which cannot be expressed as the sum of a square and a prime:
 * $1, 10, 25, 34, 58, 64, 85, 91, 121, 130, 169, 196, 214, 226, 289, 324, 370, 400, 526, 529, 625, 676, 706, \ldots$