Monday's bond sale was Apple's third such sale in as many years and was just over half the $12bn the company raised in April 2014.
The California-based firm plans to return more than $130bn to shareholders by the end of this year.
The move comes despite the company sitting on a cash pile of $178bn.
Some of the bonds are set to mature in five years, while others will not do so for another three decades.
Analysts have said that Apple could increase the amount it returns to its investors to as much as $200bn over the next three years.
Even when Apple's $35bn of debt is taken into account, it still has $142bn in cash.
Almost 90% of the cash is held outside the US, and it would have to pay the top corporate tax rate of 35% if it returned the money from abroad, which is why it is borrowing the money instead.
Apple is rated by Moody's as Aa1, the second-highest available, and bonds from companies with high credit ratings are popular with investors.
Deutsche Bank and Goldman Sachs are the banks managing the capital-raising.
Last week, Apple reported a record quarterly profit for a public company of $18bn for the three months to 31 December, with revenue up almost 30% to $74.6bn after the new iPhone 6 proved a huge hit with consumers globally.
Shares in Apple closed up 1.25%  to $118.63 in New York on Monday, valuing the company at about $684bn.

Denis O'Brien obtained the injunction to stop RTÉ from reporting details of his personal finances and relationship with former Anglo Irish Bank.
Last week, a judge granted permission for the media to report details about Mr O'Brien's finances made under privilege in the Dáil (parliament).
RTÉ lawyers said as a result there was no need for the injunction to remain.
The media mogul's fortune is estimated to be around £5bn.
Following the granting of the injunction, the purchase of one of Mr O'Brien's companies was discussed in the Dáil.
The comments were made by TD Catherine Murphy under privilege.
She said Mr O'Brien owed the former Anglo Irish Bank, now the nationalised Irish Bank Resolution Corporation (IBRC), upwards of 500m euro (£362m).
Ms Murphy, an independent left-wing TD, said Mr O'Brien was attempting to pay loans back at an interest rate of just over 1%, when it was arguable that the correct rate should be over 7%.
In response to her comments, lawyers for RTÉ and the Irish Times returned to the high court to seek clarity over whether her remarks could be reported in light of the injunction.
A judge told the media organisations that he never intended nor could he order any interference with what a TD may say under privilege in the Dáil.
The application by RTÉ to have the injunction discharged relates to a planned broadcast regarding certain information regarding Mr O'Brien's relationship with IBRC.
Lawyers for Mr O'Brien said they accepted that following comments made by the Sinn Féin TD Pearse Doherty in the Dáil on Tuesday evening, there was nothing in the proposed RTÉ script that had been injuncted that warranted further restraint.
The lawyer added that as far as he was concerned, the script in its entirety could be published, as a result of events that had happened outside the courtroom.
On Tuesday, Mr Doherty gave details of what he said were documents related to Mr O'Brien's IBRC loans during a debate in the Dáil.
The Sinn Féin finance spokesman said he had documents which led to questions about the way IBRC was run in the public interest.
US technology giant Apple raised a better than expected $6.5bn (£4.3bn) through a corporate bond sale, as part of a plan to return cash to investors.
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Irish state broadcaster RTÉ is trying to get an injunction granted to Ireland's richest man discharged.