It's all Greek to me

"You expect me to read this?"
"Don't be so old fashioned. It's the future now; just text the letters 2778 to 15924 for the code."

19 + 28 + 37
34 + 46 + 79
19 + 28 + 37 + 56
17 + 24 + 39 + 46 + 68
17 + 25 + 36 + 46