A bit, a nibble or byte? Inspired by this challenge
Given an integer in the range 0 &lt;= n &lt; 2**64, output the minimum sized container it can fit in out of

bit: 1
nibble: 4
byte: 8
short: 16
int: 32
long: 64

Testcases:
0 -&gt; 1
1 -&gt; 1
2 -&gt; 4
15 -&gt; 4
16 -&gt; 8
123 -&gt; 8
260 -&gt; 16
131313 -&gt; 32
34359750709 -&gt; 64

This is code-golf, so the shortest answer in bytes wins.
Python, 39 bytes



f=lambda n:4**(n&gt;1)*(n&lt;16)or 2*f(n**.5)


Counts how many times one must take the square root for n to be below 16, with some special-casing to avoid outputs of 2.

If 2 were included, we could do

f=lambda n:n&lt;2or 2*f(n**.5)


with True for 1.



41 bytes:

f=lambda n,i=1:i*(2**i&gt;n)or f(n,i&lt;&lt;1+i%2)


Repeatedly doubles the exponent i until 2**i&gt;n. Skips from i=1 to i=4 by shifting an additional bit when i is odd.

Alt 45 bytes:

f=lambda n,i=4:4**(n&gt;1)*(2**i&gt;n)or 2*f(n,i*2)