According to Wikipedia, it looks as though more than 10,000 Judeans were deported to Babylon. At the end of the captivity the exiled Jews numbered around 130,000 people, and around 40,000 returned to Judah. This leaves around 90,000 people to be divided between staying in Babylon, and dispersing throughout the world.
According to the Babylonian Chronicles, in 599 BC, Nebuchadrezzar II of Babylon lay siege to Jerusalem. Jehoiakim, the king of Judah, died in 598 BC during the siege, and was succeeded by his son Jeconiah at an age of either eight or eighteen. The city fell about three months later, on 2 Adar (March 16) 597 BC. Nebuchadnezzar pillaged both Jerusalem and the Temple, carting all his spoils to Babylon. Jeconiah and his court and other prominent citizens and craftsmen, along with a sizable portion of the Jewish population of Judah, numbering about 10,000 were deported from the land and dispersed throughout the Babylonian Empire. (2 Kings 24:14) Among them was Ezekiel. Nebuchadnezzar appointed Zedekiah, Jehoiakim's brother, king of the reduced kingdom, who was made a tributary of Babylon. Babylonian captivity is counted as having started with the first deportation in 597 BC. The exiles in Babylon continued to consider Jeconiah as the rightful king, and not Zedekiah. Jeconiah was counted as the first Exilarch.
Despite the strong remonstrances of Jeremiah and others, Zedekiah revolted against Nebuchadrezzar, ceasing to pay tribute to him and entered into an alliance with Pharaoh Hophra of Egypt. In 589 BC, Nebuchadnezzar returned to Judah and again besieged Jerusalem for eighteen months. During this period, many Jews fled to surrounding Moab, Ammon, Edom and other countries to seek refuge. (Jeremiah 40:11-12) The city fell and Nebuchadnezzar again pillaged both Jerusalem and the Temple, after which he destroyed them both. He took Zedekiah to Babylon and made Judah a Babylonian province, called Yehud, putting an end to the independent Kingdom of Judah. In addition to those killed during the siege, over time, some 4,600 Jews were deported after the fall of Judah. (Jeremiah 52:29)
The exile to Babylon was a traumatic event in Jewish history, as the destruction of the political independence of the kingdom coincided with the destruction of the monarchy and of the First Temple of Jerusalem. Prior to this, several deportations of Judaean nobility and leading citizens occurred.
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After the overthrow of Babylonia by the Persian Empire, the Persian ruler Cyrus the Great gave Jews permission to return to their homeland in 538 BCE, and more than 40,000 are said to have returned, as noted in the Biblical accounts of Jehoiakim, Ezra, and Nehemiah.
The Babylonian captivity had a number of consequences on Judaism and the Jewish culture, including changes to the Hebrew alphabet and changes in the fundamental practices and customs of the Jewish religion. This period saw the last high-point of Biblical prophecy in the person of Ezekiel, followed by the emergence of the central role of the Torah in Jewish life. This process coincided with the emergence of scribes and sages as Jewish leaders (see Ezra and the Pharisees).
Prior to the exile, the Israelites had been organized on a tribal basis, while afterwards they came to be organized by clans, with only the tribe of Levi continuing in its special role. After the Babylonian captivity, there were always sizable numbers of Jews living outside Eretz Israel, thus marking one starting point of the "Jewish diaspora."
During the period of captivity, Jews continued to practice and develop their religious traditions, many of which became distinct from their origins, due to the influences of the local culture.
After the overthrow of Babylonia by the Persian Empire, in 538 BC  the Persian ruler Cyrus the Great gave the Jews permission to return to their native land, and more than 40,000 are said to have availed themselves of the privilege, as noted in the Biblical accounts of Ezra, and Nehemiah. The Persians had a different political philosophy of managing conquered territories from the Babylonians or Assyrians: under the Persians, local personages were put into power to govern the local populace.
The actual return of the exiles was consummated by Ezra, who assembled at the river Ahava all those desirous of returning. These consisted of about 1,800 men, or 5,500 to 6,000 souls (Ezra viii.), besides 38 Levites and 220 slaves of the Temple from Casiphia. With this body, which was invested with royal powers, Ezra and Nehemiah succeeded, after great difficulties, in establishing the post-exilic Jewish community. From the list given in Neh. vii. 6-73 (= Ezra ii.), which the chronicler erroneously supposed to be an enumeration of those who had returned under Cyrus, it appears that the whole Jewish community at this time comprised 42,360 men, or 125,000 to 130,000 people.
There are many theories about the later descendants of early Jewish emigrations. One is that some freed Jews by Cyrus the Great migrated north following Zoroastrian Persians and established themselves in the Hindu Kush and what is now northern Afghanistan, eventually joined by a confederation of semi-nomadic Turk and Mongol tribes from Altay. They intermarried and became known as the Bulgar tribes or "people of mixed blood". Another oft-cited theory is that they became the Khazars, a Central Asian nomadic people. Some 19th century Americans believed some Native American tribes were descended from early Jewish emigrants and attempted to communicate with them in Hebrew.
Prior to the return, the northern Israelite tribes had been taken captive by Assyria and never returned, leaving the survivors of the Babylonian exile as the majority of the remaining Children of Israel. When the Israelites returned home, they found a mixture of peoples, the Samaritans, practicing a religion very similar, but not identical, to their own. Over time, hostility grew between the returning Jews and the Samaritans.
Although there are many other conflicting theories about the Samaritans' origins, many of them may have simply been Israelites who remained behind and thus had no part in the sweeping changes of the Israelite religion brought about among the captives. Alternatively, perhaps the fierce purity of the Jewish religion and cultural identity of the Babylonian Jews returning from exile, seventy years after their deportation, completely eclipsed the partial fate of the mixed group of Israelite survivors, who had practised paganism for hundreds of years in Israel (including the worship of a golden bull), and who had inter-married with the peoples sent into the territory by the Assyrians (a practice strictly forbidden by Mosaic laws , and punished by Nehemiah).
 Significance in Jewish history
The Babylonian Captivity and the subsequent return to Israel were seen as one of the pivotal events in the biblical drama between Yahweh and his people of Israel. Just as they had been predestined for, and saved from, slavery in Egypt, in the logic of the Bible it had been prophesied that the Israelites would go into captivity to the Babylonians for their idolatry and disobedience to Yahweh, and then be delivered once more. The Babylonian Captivity had a number of serious effects on Judaism and the Jewish culture. For example, the current Hebrew script was adopted during this period, replacing the traditional Israelite script.
This period saw the last high-point of Biblical prophecy in the person of Ezekiel, followed by the emergence of the central role of the Torah in Jewish life; according to many historical-critical scholars, it was edited and redacted during this time, and saw the beginning of the canonization of the Bible, which provided a central text for Jews.
This process coincided with the emergence of scribes and sages as Jewish leaders (see Ezra). Prior to exile, the people of Israel had been organized according to tribe; afterwards, they were organized by clans, only the tribe of Levi continuing in its 'special role'. After this time, there were always sizable numbers of Jews living outside Eretz Israel; thus, it also marks the beginning of the "Jewish diaspora", unless this is considered to have begun with the Assyrian Captivity of Israel.
In Rabbinic literature, Babylon was one of a number of metaphors for the Jewish diaspora. Most frequently the term "Babylon" meant the diaspora prior to the destruction of the Second Temple. The post-destruction term for the Jewish Diaspora was "Rome," or "Edom."
"I don't speak for God. All I have is personal opinion based on the story of continuity which runs through the bible!"