As character names:

U+324A CIRCLED NUMBER THIRTY ON BLACK SQUARE character (㉊)

As raw characters:

㉊

As a string of HTML entities:

㉊

Decoder output:

Byte number 1 is decimal 227, hex 0xE3, octal \343, binary 11100011
This is the first byte of a 3 byte sequence.

Byte number 2 is decimal 137, hex 0x89, octal \211, binary 10001001
This is continuation byte 1, expecting 1 more.

Byte number 3 is decimal 138, hex 0x8A, octal \212, binary 10001010
This is continuation byte 2, expecting 0 more.

U+324A	CIRCLED NUMBER THIRTY ON BLACK SQUARE
	= speed limit 30 km/h