As character names:

U+03F9 GREEK CAPITAL LUNATE SIGMA SYMBOL character (Ϲ)

As raw characters:

Ϲ

As a string of HTML entities:

Ϲ

Decoder output:

Byte number 1 is decimal 207, hex 0xCF, octal \317, binary 11001111
This is the first byte of a 2 byte sequence.

Byte number 2 is decimal 185, hex 0xB9, octal \271, binary 10111001
This is continuation byte 1, expecting 0 more.

U+03F9	GREEK CAPITAL LUNATE SIGMA SYMBOL
	# 03A3 greek capital letter sigma