There is One God, One Prophet and, allegedly, one international Muslim community – the ummah. There are five daily prayers and five pillars of Islam (profession of faith, zakat, prayer, fasting during Ramadan, and pilgrimage to Mecca, the hajj, at least once in a lifetime). There are six, for Sunnis, Articles of Faith (belief in One God; the angels of God; the books of God; the prophets of God; the Day of Judgment ; and the supremacy of God’s will), seven circuits around the Kaaba (when you actually get to Mecca) and seven verses in the Fatiha, ‘the Opening’ chapter of the Qur’an, which has 114 Surahs or chapters. The Prophet had twelve wives; and the Shia have twelve Imams.
Clearly Islam has an affinity for numbers. It is hardly surprising that Muslims of the classical period spent a great deal of time and energy in playing and thinking with numbers, measuring and calibrating things, and classifying and organising lists of branches of knowledge. ‘When I considered what people generally want’ in life, wrote al-Khwarazmi, the ninth-century astronomer and mathematician, ‘I found that it is always a number’. So he invented and wrote Algebra, a ‘work on calculating’ such things ‘as men constantly require in cases of inheritance, legacies, partition, law-suits, and trade, and in all their dealings with one another, or where the measuring of land, digging of canals, geometric computation, or other objects of various sorts and kinds are concerned’. Al-Khwarazmi’s work led Muslims to study perfect numbers and prime numbers, the summation of a finite series of integer numbers and develop the theory of numbers.