This is the 13186th most frequent Russian word.
миллионные
"Millionth" or "pertaining to millions."
The word 'миллионные' (translated as 'million-dollar') is used to specify something associated with millions, here referring to the scale of income.
Он получил миллионный доход благодаря своему успешному бизнесу.
He achieved a million-dollar income thanks to his successful business.
In this sentence, 'миллионные' (translated as 'millions of masses') modifies 'массы', emphasizing the large number of individuals involved.
Миллионные массы людей участвовали в протестах по всему миру.
Millions of masses of people participated in protests worldwide.
Here, 'миллионные' (translated as 'millions of sparks') exemplifies an immense quantity, stressing the visual richness and number of sparks observed.