Srimad Bhagavatam Canto 11, Chapter 16, Text 39

SB 11.16.39

sankhyanam paramanunam
 kalena kriyate maya
na tatha me vibhutinam
 srjato ’ndani kotisah
 
Translation: 
 
Even though over a period of time I might count all the atoms of the universe, I could not count all of My opulences which I manifest within innumerable universes.
 
Purport: 
 
The Lord here explains that Uddhava should not expect a complete catalog of the Lord’s opulences, since even the Lord Himself finds no limit to such opulences. According to Srila Jiva Gosvami, kalena indicates that the Supreme Personality of Godhead is within every atom and can therefore easily calculate the total number of atoms. However, although the Lord is certainly omniscient, even He Himself cannot supply a finite number for His opulences, because they are infinite.
Srimad Bhagavatam Canto 11, Chapter 16, Text 38
Srimad Bhagavatam Canto 11, Chapter 16, Text 40