$14.$ Consider each of these numeric literal constants. COMPUTATIONALLY, does it represent an integer? EXPLAIN.

$($a$)344513\mathrm{.}000000000000000000000000001$

$($b$)344513\mathrm{.}000000000000000000000000000$

$($c$)-5281023984$

$($d$)1$E$+18$