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Willem Klein: Biography, Achievements & Lasting Legacy

By Geniuses.Club Editorial Team | August 02, 2026 | 1912–1986
Portrait of Willem Klein
Willem Klein

Who Was Willem Klein?

Willem Klein (4 December 1912 – 1 August 1986), also known as Wim Klein or under his stage names Pascal and Willy Wortel, was a Dutch mental calculator, famous for ability to perform very complicated calculations in his head very fast. On 27 August 1976, he calculated the 73rd root of a 500-digit number in 2 minutes and 43 seconds. This feat was recorded by the Guinness Book of Records.

In 1986, Klein was killed with a knife attack within his home in Amsterdam. A suspect was arrested, but he was released due to insufficient evidence. Klein's murder remains unsolved.

Key Facts

Legacy and Impact

The influence of Willem Klein extends far beyond his own lifetime. He fundamentally shaped human knowledge and progress, and his achievements and contributions remain foundational to this day.

Though he passed away in 1986, his ideas continue to be studied, debated, and built upon by scholars and practitioners worldwide.

Willem Klein remains one of the most celebrated minds to emerge from Netherlands, a testament to the rich intellectual heritage of the region.

Notable Geniuses from Netherlands

Netherlands has produced many remarkable minds. Alongside Willem Klein:

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