4558

Number
$4558$ (four thousand, five hundred and fifty-eight) is:
 * $2 \times 43 \times 53$


 * The $43$rd heptagonal number after $1, 7, 18, 34, 55, 81, 112, \ldots, 3010, 3186, 3367, 3553, 3744, 3940, 4141, 4347$:
 * $4558 = \displaystyle \sum_{k \mathop = 1}^{43} \left({5 k - 4}\right) = \dfrac {43 \left({5 \times 43 - 3}\right)} 2$