It looks like you’re asking for a or explanation of the string "c39t36l" .

But that’s just digit mapping — to get a numeric value, you’d compute: (12 * 36^6) + (3 * 36^5) + (9 * 36^4) + (29 * 36^3) + (3 * 36^2) + (6 * 36^1) + 21 .