1 === mul ===
   2 4611686014132420600
   3 36893488130239234000
   4 === self_mul ===
   5 4611686014132420600
   6 36893488130239234000
   7 === sub ===
   8 4294967294
   9 18446744073709552000
  10 === self_sub ===
  11 4294967294
  12 18446744073709552000
  13 === add ===
  14 4294967294
  15 18446744073709552000
  16 === self_add ===
  17 4294967294
  18 18446744073709552000