Date:- 02 June 2000. 153 is a neat number. Here are four reasons: (1.) 153= 1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17 (2.) 153 = 1! + 2! + 3! + 4! + 5! = 1 + (1*2) + (1*2*3) + (1*2*3*4) + (1*2*3*4*5). (3.) 153 = 1^3 + 5^3 + 3^3 = (1*1*1) + (5*5*5) + (3*3*3) (4.) 153 lies dormant in every third number, [i.e., all multiples of 3]. Take any multiple of three, sum the cubes of its digits, take the result, sum the cubes of its digits, take the results. etc. Believe me, you eventually get 153. Take 12, for example. 1^3 + 2^3 = 9. 9^3 = 729. 7^3 + 2^3 + 9^3 = 1080. 1^3 + 0^3 + 8^3 + 0^3 = 513. Finally, 5^3 + 1^3 + 3^3 = 153 [ Bingo..!! ]