We know, smallest 7− digit number
=10,00,000
The next four numbers in ascending order are
10,00,001<10,00,001+1<10,00,002+1<10,00,003+1
⇒10,00,001<10,00,002<10,00,003<10,00,004.
Hence, the required numbers are 1000001;1000002;1000003;1000004.