22537...22347 (80-digits)

This number is a prime.

                                                                  2253721123
2223552133 3322729235 3122222311 2175722333 7219313222 5412374322 1133522347

Prime string of consecutive integers from 20 to 47 whereby the composite numbers are replaced by the concatenation of their prime factors (counting multiplicity) {2*2*5}{3*7}...{2*23}{47}. Replacing the composites by the sum of these prime factors yields yet another prime of length 53 or {9}{10}...{25}{47}. [De Geest]