The correct output when checking if the year 2021 is a leap year would be:
2021 is not a leap year.
This is because 2021 does not meet the criteria for a leap year. A year is a leap year if:
- It is divisible by 4.
- It is not divisible by 100, unless it is also divisible by 400.
Since 2021 is not divisible by 4, it does not qualify as a leap year.