DES MOINES, Iowa  — Lottery officials on Thursday raised the Mega Millions grand prize to $660 million, giving players a shot at the nation’s ninth largest jackpot.

The jackpot for Friday night’s drawing has grown so large because there hasn’t been a winner in three months. Those 27 consecutive drawings without anyone matching all six numbers has allowed the jackpot to gradually grow from its $20 million starting point in April.

Even as the big prize has increased, the odds of winning all that money have remained the same — a staggering one in 302.5 million.

The highlighted pre-tax $660 million prize is for a winner who takes an annuity option, paid out in 30 annual payments. Most players choose the cash option, which for Friday’s drawing would be $376.9 million.

Mega Millions is played in 45 states as well as Washington, D.C., and the U.S. Virgin Islands. The game is overseen by state lottery officials.