In Islam, the Devil is known as Iblīs (Arabic: إبليس), Shayṭān, (Arabic: شيطان, plural: شياطين shayāṭīn) or Shaitan. His primary activity is to incite humans to commit evil and lead the wrong path through deception. which is referred to as "whispering into the hearts". The Quran mentions that satans are the assistants of those who disbelieve in God: "We have made the evil ones friends to those without faith."
Muhammad said that every man has his own Shaitan (Satan). Some Shaitan is attached to bad people and makes them evil. Such gangs of people are called Shayateen.
it actually means that It is a human weakness. Shaitan runs in the blood of human beings. Muhammad's shaitan became a Muslim,(he said it) it means it can't call him towards evil. Khata (mistake) is not a evil/sin, just mishap. No prophet of God is exempt from Shaitan. These are human weaknesses. Vision of Hadhrat Moses (as) while traveling along the sea coast when the fish got lost. He said Shaitan made him forget it.
There is other Shaitan who calls towards evil thing. Other Shaitan doesn't call towards sins but it causes human errors. No human is exempt from it. It was a word used in olden times for 'evil mind' of a human.