The concept of a devil, or Satan often seems like a Christian concept. Is there any notion or reference to Satan in the Old Testament?

1 And he shewed me Joshua the high priest standing before the angel of the Lord, and Satan standing at his right hand to resist him.
2 And the Lord said unto Satan, The Lord rebuke thee, O Satan; even the Lord that hath chosen Jerusalem rebuke thee: is not this a brand plucked out of the fire?

Zechariah 3:1-2 (KJV)

1 And Satan stood up against Israel, and provoked David to number Israel.
2 And David said to Joab and to the rulers of the people, Go, number Israel from Beersheba even to Dan; and bring the number of them to me, that I may know it.

1 Chronicles 21:1-2 (KJV)

6 Now there was a day when the sons of God came to present themselves before the Lord, and Satan came also among them.
7 And the Lord said unto Satan, Whence comest thou? Then Satan answered the Lord, and said, From going to and fro in the earth, and from walking up and down in it.

Job 1:6-7 (KJV)

• Clearly the idea of Satan exists in the Torah.
• The Hebrew is Ha-Shatan
• The word literally means the Accuser or the Adversary