The number 23 has 3 at ones place and 2 at tens place.
968 had 9 at hundereds place, 6 at tens place and 8 at ones place.
7542 has 7 at thousands place, 5 at hundreds place, 4 at tens place and 2 at ones place.
23574 has 2 at ten thousands place, 3 at thousands place, 5 at hundreds place, 7 at tens place and 4 at ones place.
596840 has 5 at lakhs place, 9 at ten thousands place, 6 at thousands place, 8 at hundreds place, 4 at tens place and 0 at ones place.
As the number of digits increases, the value of the number increases.
Hence, 596840 > 23574 > 7542 > 968 > 23.