the numbers are only dividable by 1 or themselves, the so
called, 'prime numbers', so the next one would be 17.
The numbers are all prime in increasing order. The next number
11 comes next.
The number 7 comes next.
17 cause it is the next prime number
59 is the next number in this series.
The next number in the series is 67.
The next number in the series is 13112221.