This is Taro, who is studying about clock products.
This time it is a question about Real Time Clock.

32.768 kHz is the mainstream frequency for oscillators and oscillators used in devices that keep time such as clocks.
Why such a half-baked frequency? I think 100 kHz or 50 kHz would be better. .

Instead of using 32.768 kHz as is, divide it down and use it at a lower frequency.
32.768 kHz can be divided 15 times to make exactly 1 second.

However, if we want to make exactly one second, I thought that we could prepare an oscillator of 16.384 kHz, which is half of 32.768 kHz, and save the trouble of frequency division.

Now, representing 32768 in binary, we get

, and it will be 1 second when the most significant bit of the 16-bit counter becomes 1.
It is more convenient than 16.384 kHz because it is managed by 8 bit, 16 bit, 32 bit, etc. in electronic circuits.
Some Real Time Clock products are not only 32.768 kHz, but also 4096 Hz / 8192 Hz programmable using I2C interface.
Even if you say "Real Time Clock" in one word, it is necessary to use various things properly depending on the design. Clock products are deep!

Based on the above points, 32.768 kHz can be said to be the optimum frequency for Real Time Clock. 32.768 kHz is by no means a halfway frequency!
I blushed and agreed.