echo(073032097109032116104101032118101114121032109111100101108032111102032097032109111100101114110032109097106111114032103101110101114097108046);
E
If you use a leading zero, the number is interpreted by PHP as an octal number. Thus, a 9 is not a valid part of the number and the parser stops there:
9
0730320 (base 8) = 7 * 8^5 + 3 * 8^4 + 3 * 8^2 + 2 * 8^1 = 7 * 32768 + 3 * 4096 + 3 * 64 + 2 * 8 (base 10) = 241872 (base 10)