Hayes is from the Old English hege (hedge, enclosure) — historically a male surname now crossing into feminine given-name usage. Rutherford B. The name has surged for girls in 2010s-2020s American naming alongside other Y2K-male-becoming-feminine names (Reagan, Quinn, Reese).
Hayes 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 Hayes reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.