324

Number
$324$ (three hundred and twenty-four) is:


 * $2^2 \times 3^4$


 * The $18$th square number after $1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256, 289$:
 * $324 = 18 \times 18$


 * The $26$th untouchable number after $2, 5, 52, 88, 96, 120, 124, \ldots, 262, 268, 276, 288, 290, 292, 304, 306, 322$.


 * The $13$th positive integer after $64, 96, 128, 144, 160, 192, 216, 224, 240, 256, 288, 320$ with $6$ or more prime factors:
 * $324 = 2 \times 2 \times 3 \times 3 \times 3 \times 3$


 * The $9$th positive integer after $200, 202, 204, 205, 206, 208, 320, 322$ that cannot be made into a prime number by changing just $1$ digit


 * The $16$th positive integer which cannot be expressed as the sum of a square and a prime:
 * $1, 10, 25, 34, 58, 64, 85, 91, 121, 130, 169, 196, 214, 226, 289, 324, \ldots$