874

Number
$874$ (eight hundred and seventy-four) is:
 * $2 \times 19 \times 23$


 * The $19$th heptagonal number after $1, 7, 18, 34, 55, 81, 112, 148, 189, 235, 286, 342, 403, 469, 540, 616, 697, 783$:
 * $874 = \displaystyle \sum_{k \mathop = 1}^{19} \left({5 k - 4}\right) = \dfrac {19 \left({5 \times 19 - 3}\right)} 2$