The next number in the sequence is 15. The pattern is as follows: from 1 to 6 is +5, from 6 to 9 +4, from 9 to 12 +3, from 12 to 14 +2, and then from 14 to the answer (15) +1.
59 is the next number in this series.
One number does not make a sequence (nor a series).
243
The next number is 1112.
10
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
8
243
25
108
20