The estimated annuity jackpot for the Friday, October 19 Mega Millions drawing has been raised to $1 billion. The estimated cash value is $565.6 million.

It marks the largest jackpot in Mega Millions history and the second-largest in lottery history, trailing only the $1.586 billion Powerball jackpot in January of 2016.

The previous record Mega Millions jackpot was $656 million, shared by winners in Kansas, Illinois, and Maryland in March of 2012.

“This is truly uncharted territory, and it’s exciting to see people across the country buying their tickets and joining in the fun,” said Gordon Medenica, Mega Millions Lead Director and the Director of Maryland Lottery and Gaming. “ Hitting the $1 billion mark for the first time is historic, and we can’t wait to meet the winner s who will share in that history.”

The Mega Millions jackpot has been building since it was last hit on July 24, when a group of 11 co-workers in California shared a $543 million jackpot.

The jackpot isn’t the only prize: In the 24 drawings since July 24, more than 22 million winning tickets have been sold across the game’s nine prize levels, including 34 winners of at least $1 million.

If the October 19 jackpot is not hit, the next jackpot would be estimated at $1.6 billion.

Mega Millions tickets are $2 and are sold in 44 states, Washington, D.C., and the U.S. Virgin Islands. Drawings are held at 11 p.m. on Tuesdays and Fridays.