Yes, 666 is the devils number, but maybe there’s other interpretations.
B’sha’ah tova, Rebecca — congratulations on the upcoming birth of your baby. I hope that all goes well for you and the baby. You write that the pregnancy is leading your husband to connect with his Jewish roots in new ways. Becoming a parent can do that to you. If you want to read more about it, I recommend Chana Weisberg’s book “Expecting Miracles: Finding Meaning and Spirituality in Pregnancy Through Judaism” (Urim Publications 2004).