1288

Number
$1288$ (one thousand, two hundred and eighty-eight) is:
 * $2^3 \times 7 \times 23$


 * The $23$rd heptagonal number after $1$, $7$, $18$, $34$, $55$, $81$, $112$, $148$, $189$, $235$, $286$, $342$, $403$, $469$, $540$, $616$, $697$, $783$, $874$, $970$, $1071$, $1177$:
 * $1288 = \ds \sum_{k \mathop = 1}^{23} \paren {5 k - 4} = \dfrac {23 \paren {5 \times 23 - 3} } 2$