C:\>perl -MDevel::Peek -le "$x = 2 ** 3; Dump $x;"
SV = NV(0x47cd88) at 0x47cda0
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 8

C:\>perl -MDevel::Peek -le "$x = 2 ** 49; Dump $x;"
SV = NV(0x33d148) at 0x33d160
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 562949953421312

C:\>perl -MDevel::Peek -le "$x = 2 ** 50; Dump $x;"
SV = NV(0x47cd38) at 0x47cd50
  REFCNT = 1
  FLAGS = (NOK,pNOK)
  NV = 1.12589990684262e+15