Thirty-seven is prime and has a set of arithmetical properties that number-mystics have long enjoyed. It is the factor of the repunits: one hundred and eleven is three times thirty-seven, and every three-digit repdigit, two hundred and twenty-two, three hundred and thirty-three, up to nine hundred and ninety-nine, is divisible by thirty-seven, because a hundred and eleven is. It is also one of the mirror primes, its reverse seventy-three being prime as well, and the two multiply to two thousand seven hundred and one, which is the gematria of the opening verse of Genesis, In the beginning God created the heavens and the earth, a coincidence much prized in Jewish arithmetical exegesis, since two thousand seven hundred and one is thirty-seven times seventy-three and also a triangular number.
Unlike many of the higher compound numbers in his scheme, Cheiro's 1926 Book of Numbers gives thirty-seven a description entirely its own rather than pointing back to a lower number: a distinct potency, good and fortunate friendships in love and in combinations with the opposite sex, favourable for partnerships of every kind and a fortunate sign wherever it appears in calculations touching future events, one of the more consistently positive readings in the whole compound-number scheme.