The phrase "and a hefty number" is correct and usable in written English.
It can be used to indicate a large quantity or significant amount of something, often in a casual or informal context.
Example: "The event attracted a hefty number of attendees, far exceeding our expectations."
Alternatives: "and a large number" or "and a significant number".
He was also ahead of most of the Red Sox hitters, and threw a hefty number of off-speed pitches for strikes.
Many visitors bunk down in the ancient city of Nicosia -- Cyprus' capital and home to a hefty number of the island's 100 or so tourist-class hotels -- and in the modern-day resort cities of Limassol, Larnaka and Agia Napa.
This season we have a hefty number of plays and even musicals dealing with subjects that might be said to have been ripped from the op-ed pages (although slightly yellowed pages).
With a hefty number of 3D and 2D theaters scheduled to show the film, chances are this action epic will rake in a decent number.
Plus, shooters are known to employ widely available semi-automatic firearms, handguns or otherwise, which make it easy to squeeze off a hefty number of rounds and trust in the quantity rather than the quality of one's shots to strike a desired target.
In part, that's come from the "discovery" of Alamos by expats from across the globe, including a hefty number from the U.S. and Canada.
With an accelerated year of development, a successful demo at HAXLR8R, a hefty number of social followers, and a strong media presence, Prynt is well-situated to take 2015's crowdfunding cake.
Glow's competition includes a hefty number of websites, mobile apps and even wearables to help couples get or avoid getting pregnant.
According to ComScore, Android has 52percentt of the U.S. smartphone install base, while iOS has 41percentt – a hefty number in either case, but Android is larger and growing.
