Year 163 (CLXIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Laelianus and Pastor (or, less frequently, year 916 Ab urbe condita). The denomination 163 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

In number theory, a Heegner number is a square-free positive integer d such that the imaginary quadratic field Q has class number 1. Equivalently, its ring of integers has unique factorization.

Year 163 (CLXIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Laelianus and Pastor (or, less frequently, year 916 Ab urbe condita). The denomination 163 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

In number theory, a Heegner number is a square-free positive integer d such that the imaginary quadratic field Q has class number 1. Equivalently, its ring of integers has unique factorization.