Unstyled:
1	x
12	x
123	x
1234	x
12345	x
123456	x
1234567	x
12345678	x
123456789	x
1234567890	x
12345678901	x
123456789013	x
1234567890123	x
With letter-spacing:
1	x
12	x
123	x
1234	x
12345	x
123456	x
1234567	x
12345678	x
123456789	x
1234567890	x
12345678901	x
123456789013	x
1234567890123	x
With word-spacing:
1	x
12	x
123	x
1234	x
12345	x
123456	x
1234567	x
1234567 	x
1234567 9	x
1234567 90	x
1234567 901	x
1234567 9013	x
1234567 90123	x