Problem Statement

Primorial numbers are those formed by multiplying successive prime numbers.

The primorial number series is: To express this mathematically,   primorialn   is   the product of the first   n   (successive) primes:

In some sense, generating primorial numbers is similar to factorials. As with factorials, primorial numbers get large quickly.

By   length   (above), it is meant the number of decimal digits in the numbers.

Let's start with the solution:

primes: [2] ++ select.first: 99999 range.step: 2 3 ∞ => prime?

primorial: function [n][
    if 0 = n -> return 1
    product take primes n
]

print "First ten primorials:"
loop 0..9 => [print primorial &]
print ""
loop 1..5 'm -> print [
    "primorial" 10^m "has" size ~"|primorial 10^m|" "digits"
]