hat is the next number in the series: 60 30 20 15 12
59 is the next number in this series.
The next number in the series is 13112221.
There is no series: one number, however large, does not make a 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!
The next number is 4. There is a sequence:Add 3, subtract 2, repeat
Look at the difference between each number and the next number.
The next number is -57
The next number is 1112.
The sum of the previous two numbers in the series.
3467910 is a single number: it is not a pattern!