Without knowing the context, it's difficult to be sure.
- It could be simply a decimal number, 6,245, with leading zeros.
- In computer programming, it is customary to write base 8 (octal) numbers with leading zeros. This could be a number in base 8, since it doesn't contain any digits greater than 7. In that case, 0000006245 would be equivalent to 3,237 in base 10.
- There is the remote possibility that it is a number in a higher base, like base 16 (hexadecimal), but there is no clue to suggest that or indicate what the base might be.
In any of those cases, the leading zeros are not significant.