The definition given in the article is an informal shortcut, the complete definition is http://mathworld.wolfram.com/DeletablePrime.html http://mathworld.wolfra

The definition given in the article is an informal shortcut, the complete definition is http://mathworld.wolfram.com/DeletablePrime.html http://mathworld.wolfram.com/DeletablePrime.html and 1987 is indeed a deletable prime (see http://oeis.org/A080608/b080608.txt http://oeis.org/A080608/b080608.txt for http://oeis.org/A080608 http://oeis.org/A080608).