He was told the bullet lodged in his body would set off the security alarms at airports, but so far it has not. There were no stitches administered to close the wound, but that does not mean the healing process was seamless for Corey Ballentine.

The rookie cornerback is one of the loudest stories of the summer for the Giants. He survived a horrific shooting and watched a college teammate — one of his closest friends — suffer a fatal gunshot blast. The mental scar of seeing Dwane Simmons, 23, murdered on the street is something Ballentine has had to deal with since April 28 and most likely for the rest of his life. What is not commonly known is how much physical peril Ballentine endured to emerge as one of the most promising unsung newcomers on the Giants’ roster.

The night the Giants made Ballentine a sixth-round draft pick out of Washburn University in Topeka, Kan., Ballentine and Simmons were outside a campus party when a vehicle pulled up and someone inside began firing. An 18-year-old was arrested and faces murder and battery charges in the attack.

“It was worse than what people thought it was,’’ Ballentine told The Post on Tuesday, referring to the injuries he sustained.

The bullet ripped into Ballentine’s body through the buttocks and traveled into his hip bone, causing a crack. It caused intense pain in both of his hips and left him unable to walk.

That night, a doctor attending to Ballentine said he would not be able to run for at least six weeks. This was sobering news for a youngster eager to make an impression with his new NFL team.

“Bones heal,’’ Ballentine said. “I’m just glad it wasn’t worse. It could have hit an artery or something like that. I’m really just glad I could recover from it and I’m still here.’’

Ballentine is more than merely here. He beat the timetable the doctors set for him, able to run about a month after the shooting. It has been an upward trajectory. Ballentine went from a player looking to find a place on the roster to a player seeking a role on the defense, his spot on the team already secure.

“I don’t think it’s been smooth,’’ Ballentine said. “I’ve been learning a lot. There’s a lot being thrown at me and it’s just up to me to be a pro. It looks smooth, but there’s a lot of work that goes into it as well. A lot of long nights staying up watching plays.’’

It easily could have all been too big for Ballentine. He played at the Division II level in college, where NFL players are scarce.

A solid showing at the Senior Bowl helped ease his mind, a first test he passed. Once he healed and was able to make up for the time he missed, Ballentine started impressing the Giants coaching staff and really has never stopped.

“I think anytime we have adversity in our life, it becomes part of us,’’ coach Pat Shurmur said. “You hate to see somebody go through that, but the way he’s handled it emotionally, mentally, his conversations in the building, asking for people to help him. He displayed to us that he’s a very smart, very mature young man. He’s got a great, really a high degree of toughness to him.’’

At 6-feet and 190 pounds, Ballentine looks the part, although he acknowledges there is a vast difference between covering Division II wide receivers — “I was taller than most of them and I weighed a little bit more than most of them’’ — and NFL targets.

“Here, everybody’s like 6-2 or taller,’’ Ballentine said. “Everybody’s taller on average, bigger on average, faster on average. I think the people here have better playmaking abilities as far as going up to get the ball. I think I can compete with them, so I’m not too worried about it.’’

He remains grounded. Asked if he has carved out a spot on the defense, Ballentine said, “I’m not gonna say the spot is there with me and it just has my name on it.’’

Ballentine said he does not feel the bullet, which remains an unwelcome intruder in his body, though doctors have prescribed medicine to offset any negative effects from the lead in the bullet. The physical pain is no longer there, but he is forever changed by that awful night when those shots rang out.

“What it really taught me was I’ve been through so much to get here, you know, and I never realized, I don’t think I gave myself enough credit for the things I’ve had to push though as far as adversity,’’ Ballentine said. “Just pushing through that, it kinda put things in perspective. It was kinda like ‘You’re stronger than you think you are mentally.’ ’’