273

Number

$273$ (two hundred and seventy-three) is:

$3 \times 7 \times 13$

The $28$th sphenic number after $30$, $42$, $66$, $70$, $\ldots$, $182$, $186$, $190$, $195$, $222$, $230$, $231$, $246$, $255$, $258$, $266$:

$273 = 3 \times 7 \times 13$

The $51$st lucky number:

$1$, $3$, $7$, $9$, $13$, $15$, $21$, $\ldots$, $219$, $223$, $231$, $235$, $237$, $241$, $259$, $261$, $267$, $273$, $\ldots$

The $3$rd of $4$ integers $n$ such that $n + 2 n$ can be expressed as a sum using each of the digits $1$ to $9$ exactly once each:

$273 + 546 = 819$

The product with its reversal equals the product of another $3$-digit number with its reversal:

$273 \times 372 = 156 \times 651$