Go to the Minor Planet Center's Forthcoming Close Approaches To The Earth (1900-2178) page and search for 2002 NT7. You'll find the following entries (edited to remove unnecessary fields). One Au is the mean distance between the Earth's orbit and the Sun, roughtly 93 million miles or 150 million kilometers. Multiply the Au value by 93 million miles (or 150 million kilometers) to get the distance to the closest approach.

Date Au
1900 Feb. 8.80 0.1701
1916 Feb. 10.92 0.1957
2083 Jan. 23.48 0.1985
2099 Jan. 23.91 0.1889

The 2083 approach will be roughly 1.85 million miles away. The 2099 approach will be a bit closer at 1.76 million miles. Looks like there won't be any close calls anytime soon for 2002 NT7.

Now, if you want to see their listing of Potentially Hazardous Asteroids (PHAs), simply click on the link. The closest known approach for all of the cataloged objects is:

2001 WN5 2039 June 26.96 0.001485

That value of 0.001485 Au is approximately 138,000 miles, which is closer than the distance from the Earth to the moon.