use Devel::Peek;

my $x = 42;
Dump $x;

print "$x\n";   # <-- conversion to string behind the scenes
Dump $x;

__END__
SV = IV(0x62de18) at 0x604fa0
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,IOK,pIOK)
  IV = 42

42
SV = PVIV(0x606130) at 0x604fa0
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,IOK,POK,pIOK,pPOK)
  IV = 42
  PV = 0x624fb0 "42"\0
  CUR = 2
  LEN = 8