What is principal financial group phone number? Phone Number of Principal Financial Group is +1-800-986-3343 . Principal Financial Group is a well known “Finance and Insurance” company which is committed to provide Banking, Life Insurance, Mutual Funds and Retirement Plans and other services to the world-wide businesses, inpiduals and institutional clients.What is a principal number? Principal quantum number. In quantum mechanics, the principal quantum number (symbolized n) is one of four quantum numbers which are assigned to all electrons in an atom to describe that electron's state. As a discrete variable, the principal quantum number is always an integer.What is a principal contact? The principal contact is the organization's staff person principally responsible for day-to-day PCN activities.