Number 33 is a special number in numerology. Its a very constructive and unique in many ways. This is one number which can be used for spirituality as well as material possessions. The root energy of number 33 stems from spiritual significance. As many attributes are given for number 33, some are number of riches, number of tantra and mantra, and the number of Kali - the goddess.
Number 33, like number 66 is unique, the presence of jupiterian number 3o and 3 combines to form a number of venus. Its a perfect energy flow from ying to yang. The significance of number 33 is paramount. Its a number which was used for healing purposes, and still woman who cant concieve have used name number 33 for producing offsprings effectively. As i once said in my post about Numerology and Childbirth, the energy of jupiter denotes the fertility of sexual energy and energy of venus denotes the quantity and rate of production of life force (sperm or ovum). The number 33 promises the greater fertility and pure energy of life force with accelerated rate to bestow tremedous spiritual energy in oneself.
Thats the reason, this number was considered of spiritual importance as it does physiological wonder.