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.
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。