10 (1/2, 2/3, 3/4, 4/5, 5/6 etc)
How about 10 which is also a factor of 60
59 is the next number in this series.
The next number in the series is 67.
A single number such as 61205041320 does not make a series.
A single number, such as 12848384 does not make a series.
One number does not make a sequence (nor a series).
There is no series of number: just one very large number!
73791170
20
8
243
25
108