1-digit prime factors: 3
2-digit prime factors: 4
3-digit prime factors: 8
4-digit prime factors: 15
5-digit prime factors: 33
6-digit prime factors: 79
7-digit prime factors: 141
8-digit prime factors: 342
9-digit prime factors: 709
10-digit prime factors: 1384
11-digit prime factors: 2856
12-digit prime factors: 5462
13-digit prime factors: 10727

Number of known prime numbers: 21763 (261089 digits)

Perl script written by Dario Alejandro Alpern. Last updated on January 25th, 2004.