pdftk binary package in Ubuntu Xenial arm64

 If PDF is electronic paper, then PDFtk is an electronic stapler-remover,
 hole-punch, binder, secret-decoder-ring, and X-Ray-glasses. PDFtk is a
 simple tool for doing everyday things with PDF documents. Keep one in the
 top drawer of your desktop and use it to:
  - Merge PDF documents
  - Split PDF pages into a new document
  - Decrypt input as necessary (password required)
  - Encrypt output as desired
  - Fill PDF Forms with FDF Data and/or Flatten Forms
  - Apply a Background Watermark
  - Report PDF on metrics, including metadata and bookmarks
  - Update PDF Metadata
  - Attach Files to PDF Pages or the PDF Document
  - Unpack PDF Attachments
  - Burst a PDF document into single pages
  - Uncompress and re-compress page streams
  - Repair corrupted PDF (where possible)

Source package