CCLVII is the number 257 in roman numerals. This is a notation used earlier for representing numbers.
C represent 100 L is used for 50 and V is used for 5. This would give you CCLVII.
257 in Roman numerals equals CCLVII
It is: 132 = CXXXII in Roman numerals
MDCCXC
294
50
X = 10
XX
72
1000
1236
L
750 = DCCL
1900