Digit Sums and Harshad Numbers
Helen G. Grundman, Ph.D.
The American Mathematical Society
A Harshad number is a positive integer that is divisible by the sum of its digits. In this talk, I will discuss research on these numbers and, more generally, on b-Harshad numbers, where b is a positive integer greater than 1. After presenting examples and basic results, I will prove that, for each b, there is a maximal length of strings of consecutive b-Harshad numbers.
Helen G. Grundman is a Research Professor Emeritus of Mathematics at Bryn Mawr College and the Director of Education and Diversity at the American Mathematical Society. She completed her undergraduate studies at the University of Michigan, graduating with secondary teaching credentials and a double major in mathematics and psychology. She then taught high school in the Detroit area, returned to school for her Ph.D. in Mathematics from the University of California, Berkeley, and held a post-doctoral position at MIT, before settling at Bryn Mawr College. Her research interests include Integer Sequences, Diophantine Equations, Galois Realizability, and Hilbert Modular Varieties. In her spare time, she enjoys puzzles, board games and card games, and (of course) math research.
