270

Number
$270$ (two hundred and seventy) is:


 * $2 \times 3^3 \times 5$


 * The $5$th Ore number after $1, 6, 28, 140$:
 * $\dfrac {270 \times \tau \left({270}\right)} {\sigma \left({270}\right)} = 6$
 * and the $4$th after $1, 6, 140$ whose divisors also have an mean which is an integer:
 * $\dfrac {\sigma \left({270}\right)} {\tau \left({270}\right)} = 45$