69

70!

71!!!!!!!!!!!!

72

the smallest number that can be written as a sum of two primes, each ending with the digit 1, in two distinct ways:

72 = 11 + 61 = 31 + 41

is the largest number of spheres that can touch another sphere in a lattice packing in 6 dimensions.

Dividing 72 by the interest rate (x percent), you obtain the number of years you should wait to double your initial capital.

= 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 (sum of consecutive even integers)

= 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 (sum of consecutive integers)

= 5 + 7 + 11 + 13 + 17 + 19 (sum of 6 consecutive primes)

= 13 + 17 + 19 + 23 (sum of 4 consecutive primes)

= (1 x 2 x 3 x 4 x 5 x 6)/(1 + 2 + 3 + 4) - G. Sarcone

= 23(23 + 1) = 32(32 - 1)

= 23 · 32

= 112 - 72 = 192 - 172 (difference of 2 consecutive squared primes)

= 23 + 43 = 34 - 32

72 = 24 x 3 and reversely 27 = 24 + 3

725 = 195 + 435 + 465 + 475 + 675

The isosceles triangle having a pair of 72° angles is called a Golden Triangle.

The Great Rhombicuboctahedron (see opposite) is an Archimedean Solid with 72 Edges.

The pulse rate of normal adult human is about 72 beats per minute at rest.

72 hours = 3 days

The 72 names of God in the Kabbalistic tradition.

Incredible geometric sculpture made with 72 pencils by the artist and mathematician George W. Hart.

SEVENTY THREE 73

74?

75!

That one number after 75!

78?