A number is a multiple of 400 if the last 4 digits are a multiple of 400 The 1,000s digit is even and the last 3 digits are 000, 400 or 800 The 1,000s digit is odd and the last 3 digits are 200 or 600 It also works checking if the number is a multiple of 16 and 25 at the same time because 400 = 2⁴ x 5² = 16 x 25
There are 2 digits in 30. They are 3 and 0.
It would be 2 raised to the power 32: 4,294,967,296.
There are 90 of them.
Four of them.
01
There are seven digits: 8,000,000
This can be solved by looking at each set of digit lengths. From 1 through 9, it's obvious there are 9 digits. From 10 through 99, there are 2 digits for each of the 90 numbers, so that makes 90*2=180 digits. Next, from 100 to 400, there are 401 numbers with 3 digits each, making another 401*3=1,203 digits. So the final answer is 9+180+1,203 = 1,392 digits.
Seven: 10, 16, 20, 25, 40, 50, 80.
A number is a multiple of 400 if the last 4 digits are a multiple of 400 The 1,000s digit is even and the last 3 digits are 000, 400 or 800 The 1,000s digit is odd and the last 3 digits are 200 or 600 It also works checking if the number is a multiple of 16 and 25 at the same time because 400 = 2⁴ x 5² = 16 x 25
400
It is 2.
10 digits
I'm sure there are more than 2 prime numbers that are 400 digits long.
2 digits are in 30
There are 2 digits in 30. They are 3 and 0.
Depends on what they are, and how many total digits.