REAL_16

 REAL(KIND=16) or REAL*16

 A REAL(KIND=16) constant has more than four times the accuracy of a
 REAL number, and a greater range.

 A REAL(KIND=16) constant occupies 16 bytes of memory.  The number
 of digits that precede the exponent is unlimited, but typically
 only the leftmost 33 digits are significant.