C:\>perl -MScalar::Util -MDevel::Peek -le "Dump(Scalar::Util::looks_like_number('abc'));"
SV = PVNV(0x726f74) at 0x723250
  REFCNT = 2147483647
  FLAGS = (IOK,NOK,POK,READONLY,pIOK,pNOK,pPOK)
  IV = 0
  NV = 0
  PV = 0x7229b4 ""\0
  CUR = 0
  LEN = 12