What are the numbers divisible by 400?

400, 800, 1200, 1600, 2000, 2400, 2800, 3200, 3600, 4000, 4400, 4800, 5200, 5600, 6000, 6400, 6800, 7200, 7600, 8000, 8400, 8800, 9200, 9600, 10000, 10400, 10800, 11200, 11600, 12000, 12400, 12800, 13200, 13600, 14000, 14400, 14800, 15200, 15600, 16000, 16400, 16800, 17200, 17600, 18000, 18400, 18800, 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22000, 22400, 22800, 23200, 23600, 24000, 24400, 24800, 25200, 25600, 26000, 26400, 26800, 27200, 27600, 28000, 28400, 28800, 29200, 29600, 30000, 30400, 30800, 31200, 31600, 32000, 32400, 32800, 33200, 33600, 34000, 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37200, 37600, 38000, 38400, 38800, 39200, 39600, 40000, 40400, 40800, 41200, 41600, 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45200, 45600, 46000, 46400, 46800, 47200, 47600, 48000, 48400, 48800, 49200, 49600, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800, 53200, 53600, 54000, 54400, 54800, 55200, 55600, 56000, 56400, 56800, 57200, 57600, 58000, 58400, 58800, 59200, 59600, 60000, 60400, 60800, 61200, 61600, 62000, 62400, 62800, 63200, 63600, 64000, 64400, 64800, 65200, 65600, 66000, 66400, 66800, 67200, 67600, 68000, 68400, 68800, 69200, 69600, 70000, 70400, 70800, 71200, 71600, 72000, 72400, 72800, 73200, 73600, 74000, 74400, 74800, 75200, 75600, 76000, 76400, 76800, 77200, 77600, 78000, 78400, 78800, 79200, 79600, 80000, 80400, 80800, 81200, 81600, 82000, 82400, 82800, 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400, 86800, 87200, 87600, 88000, 88400, 88800, 89200, 89600, 90000, 90400, 90800, 91200, 91600, 92000, 92400, 92800, 93200, 93600, 94000, 94400, 94800, 95200, 95600, 96000, 96400, 96800, 97200, 97600, 98000, 98400, 98800, 99200, 99600, 100000

There is a total of 250 numbers (up to 100000) that are divisible by 400.
The sum of these numbers is 12550000.
The arithmetic mean of these numbers is 50200.

How to find the numbers divisible by 400?

Finding all the numbers that can be divided by 400 is essentially the same as searching for the multiples of 400: if a number N is a multiple of 400, then 400 is a divisor of N.

Indeed, if we assume that N is a multiple of 400, this means there exists an integer k such that:

$k \times 400 = N$

Conversely, the result of N divided by 400 is this same integer k (without any remainder):

$k = \frac{N}{400}$

From this we can see that, theoretically, there's an infinite quantity of multiples of 400 (we can keep multiplying it by increasingly larger integers, without ever reaching the end).

However, in this instance, we've chosen to set an arbitrary limit (specifically, the multiples of 400 less than 100000):

1 × 400 = 400
2 × 400 = 800
3 × 400 = 1200
...
249 × 400 = 99600
250 × 400 = 100000