Vivian comes from the Latin vivianus, derived from vivus (alive). It was used originally for both boys and girls but has become predominantly feminine in modern English.
After decades of decline, Vivian has returned in the 2010s and now sits in the U.S.
Vivian does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Vivian reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.