title: How big can a 64bit signed integer be?
body: <p>In <a href="http://redis.io/commands/hincrby" rel="noreferrer">redis</a>,</p>
  
  <blockquote>
    <p>The range of values supported by
    HINCRBY is limited to 64 bit signed
    integers.</p>
  </blockquote>
  
  <p>And I'd like to know how big can that 64 bit signed integer be.</p>