Any number that you choose can be the next number. It is easy to find a rule based on a polynomial of order 4 such that the first four numbers are as listed in the question followed by the chosen next number. There are also non-polynomial solutions. Short of reading the mind of the person who posed the question, there is no way of determining which of the infinitely many solutions is the "correct" one.
The following rule:
t(n) = 8.49861*n^6 - 195.47917*n^5 + 1758.46527*n^4 - 7843.68747*n^3 + 18098.03605*n^2 - 20183.83326*n + 8382 gives the next number is 14289.58, approx.
108
3467910 is a single number: it is not a pattern!
Look at the difference between each number and the next number.
The next number is -21
The next number in the series 1 2 4 8 10 20 22 is
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!
8
243
20
25
73791170
108