I didn't understand this hint. 
October 1, 2020: Hint #5 Crypto string is transformed from Base58 to Decimal.
October 1, 2020: Hint #5 Crypto string is transformed from Base58 to Decimal.
Try this converter: https://brainwalletx.github.io/#converter
For example "CPD" (Base58 input) is transformed to 38292 (Decimal output)