1 week = 10080 minutes (60*24*7)
77639 calls / 10080 = 7.7 calls per minute, so every 7.8 seconds. The news article mentions she used 3 phones, though. She also used energy drinks and amphetamines to stay awake.
8 calls per minute, 4 messages per minute, 11.5 emails per hour 1.3 sung messages per hour and almost 4 letters per hour...