This is the 11529th most frequent Russian word.
достигших
"Достигших" - "those who have reached/achieved."
Here, "достигших" is used as a participle describing people who have accomplished significant achievements in science.
Люди, достигших больших высот в науке, заслуживают уважения.
People who achieved great heights in science deserve respect.
In this sentence, "достигших" describes athletes and their significant achievements.
Я читал о спортсменах, достигших выдающихся результатов.
I read about athletes who have achieved outstanding results.
Here, "достигших" refers to students who obtained impressive school performance.