Justin Timberlake's '20/20' Eyeing Half-Million Debut Sales Week, Streams Online

The long-awaited album should easily score Timberlake his second No. 1 solo set.

While Justin Timberlake's long-awaited album "The 20/20 Experience" doesn't go on sale for another week, industry sources say it's going to have a blockbuster debut on Billboard's charts.

The album became available for online streaming via iTunes on Monday, giving fans their first listen.

Those in the know suggest the album could sell at least 500,000 copies in its debut week, easily securing Timberlake his second No. 1 album on the Billboard 200 chart. "20/20's" half-million forecast could grow even larger once the album reaches retailers.

The RCA Records set, which is due to go on sale on Tuesday, March 19 in the U.S., could score the best sales week for an album in four months. The last title to sell more than a half-million in a week was One Direction's "Take Me Home," which opened with 540,000 after its release on Nov. 13, 2012 (according to Nielsen SoundScan).

Since the start of 2012, only four albums sold in excess of a half-million in a week: "Take Me Home," Mumford & Sons' "Babel" in its debut frame (600,000), Adele's "21" in the first full week after the 2012 Grammy Awards (730,000) and Taylor Swift's "Red" in its debut (1.2 million).

The last solo male artist to sell more than 500,000 in a week was Drake, when his "Take Care" album debuted with 631,000 on the chart dated Dec. 3, 2011.

Timberlake's last studio album, 2006's "FutureSex/LoveSounds," sold 684,000 in its first week, and debuted at No. 1.