I have a single premium deferred annuity of $21,000. Will I be able to get a loan against this, and if so, how much?

I depends on your specific contract.

Some insurance companies may provide loan provisions for their single premium deferred annuities.

Loan provision availability will vary from company to company.

Also, if there is a loan provision feature available, the specifics of what that feature allows will vary from product to product.

You need to look at the contract for the product you purchased or are considering purchasing.

Start by asking your financial advisor to have a look at the contract.

You may also want to go directly to the insurance company that provides the product with the same question.

Hope this helps.