Zayn Malik's debut solo single has hit number one on iTunes in 60 countries.

Zayn Malik

Zayn Malik

The 23-year-old singer released 'Pillowtalk' on Friday (29.01.16) and within minutes it was trending worldwide on Twitter before shooting to the top of the charts around the globe.

He tweeted: "Crazy love today :) This s**t is crazy ... I can't believe it. Blown away... Love you all (sic)."

The steamy video for the single features Zayn and his girlfriend Gigi Hadid having a smouldering make-out session although he has hinted he wrote the song about his former fiancée Perrie Edwards.

Zayn told Zane Lowe in an interview with Apple Music's Beats 1 that he started writing his upcoming album, 'Mind of Mine', when he was still engaged to Perrie.

And his black and white tattoo of the Little Mix star is visible on his upper right arm in the video.

The former One Direction heartthrob got the tattoo in 2013 and instead of getting rid of the inking when they split up in August 2015, Zayn got another tattoo of a lotus flower, which symbolises rebirth, weeks after they went their separate ways.