Write down three consecutive whole numbers just preceding 8510001.

We have:
First number = 8,510,001 - 1 = 8,510,000
Second number = 8,510,000 - 1 = 8,509,999
Third number = 8,509,999 - 1 = 8,509,998

Hence, the three consecutive whole numbers just preceding 8,510,001 are 8,510,000, 8,509,999 and 85,09,998.