A page of the Numeropedia - the Special Encyclopedia of Numbers
[Math.] Sum of the first 241 cube numbers:
13+23+…+2413 = 850,363,921 = (1+2+…+241)2 = 29,1612.
[Math.] 292082 = 853,107,264, the largest one of 22 squares using all 9 digits 0-8 once.
[Language] The 9-digit number whose digits are distinct and in the English alphabetical consecutive order.
[Math.] (1+2+…+18)4 = [(15+25+…+185)+(17+27+…+187)]/2.
[Math.] A regular polygon with this odd number (product of Fermat prime numbers) of sides is constructible by using only straightedge and compass. 858,993,459 = 3×17×257×65,537.
[Math.] For any xyz = 100 to 999, there are always six 6-digit numbers abc,edf such that the sum (xyz+abc,def) is equal to one of 6 digit-rotations of 142,857 and the number xyz,abc,def is a multiple of 142,857.
For any xyz = 100 to 999, there are always twelve 6-digit numbers abc,edf such that the sum (xyz+abc,def) is equal to one of 12 digit-rotations of 076,923 or 153,846 and the number xyz,abc,def is a multiple of 76,923.