Monday, May 11, 2009

30

30 = 2 x 3 x 5.

30 is the smallest number with three distinct prime divisors.

30 has a unique representation as a sum of three squares: 30 = 12 + 22 + 52.

30 is a pyramidal number (the sum of all squares of integers from 1 to 4): 30 = 12 + 22 + 32 + 42.

30 is 33 in base 9.


A dodecahedron is a Platonic solid with 30 edges.


Source:
Number Gossip

1 comment:

Gary Croft said...

30 (the 3rd primorial: 2x3x5) shapes the geometry within which the prime number sequence is distributed. To see how: http://www.primesdemystified.com and http://www.primesdemystified.com/thirty