1408

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Number

$1408$ (one thousand, four hundred and eight) is:

$2^7 \times 11$

The $22$nd octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $645$, $736$, $833$, $936$, $1045$, $1160$, $1281$:

$1408 = \ds \sum_{k \mathop = 1}^{22} \paren {6 k - 5} = 22 \paren {3 \times 22 - 2}$

Also see

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