As a divorces spouse who qualifies, you can claim against your ex-husband's work record for a benefit. You would be eligible for a benefit up to 50% of his regular OR disability benefit once you reach age 66.
Claiming at age 64 reduces that amount by approximately 13%, depending on the number of months you claim early.
If he has a maximum benefit, he could be collecting as much as $2,642 as a maximum benefit. Your divorced spouse's benefit could be up to 50% of that, or $1,321 per month.
A few factors adjust that amount:
I assumed he is collecting a max benefit. A visit to your SSA office can confirm the dollar amount of his benefit, and yours.
Your benefit must be claimed first, and that would be increased if the spousal benefit is higher.
Claiming early, at age 64, might reduce the maximum from $1,321 to $1,145 per month. If you wait until you reach age 66, your benefit will be the full 50% of his.