648

Number

$648$ (six hundred and forty-eight) is:

$2^3 \times 3^4$

The $43$rd powerful number after $1$, $4$, $8$, $9$, $16$, $25$, $\ldots$, $400$, $432$, $441$, $484$, $500$, $512$, $529$, $576$, $625$:

$648 = 2^3 \times 3^4$

The $13$th positive integer after $128$, $192$, $256$, $288$, $320$, $384$, $432$, $448$, $480$, $512$, $576$, $640$ with $7$ or more prime factors:

$648 = 2 \times 2 \times 2 \times 3 \times 3 \times 3 \times 3$

The $31$st Smith number after $4$, $22$, $27$, $58$, $\ldots$, $454$, $483$, $517$, $526$, $535$, $562$, $576$, $588$, $627$, $634$, $636$, $645$:

$6 + 4 + 8 = 2 + 2 + 2 + 3 + 3 + 3 + 3 = 18$