What does a leading zero do for a php int?

Question

echo(073032097109032116104101032118101114121032109111100101108032111102032097032109111100101114110032109097106111114032103101110101114097108046);

E

Answer 1

010 gives you 8 (octal number)
0x10 gives you 16 (hexadecimal number)