666 = 123 + 456 + 78 + 9 = 1 + 2 + 3 + 4 + 567 + 89
666 = 9 + 87 + 6 + 543 + 21
666 = 0^7 + 1^9 − 2^5 − 3^8 + 4^6 + 5^2 + 6^1 + 7^4 + 8^0 + 9^3
666 = 2^2 + 3^2 + 5^2 + 7^2 + 11^2 + 13^2 + 17^2
666 = 2 × 3 × 3 × 37 and 6 + 6 + 6 = 2 + 3 + 3 + 3 + 7.
Repdigit
666 = 1 + 2 + 3 + ... + 34 + 35 + 36 (Note 36 = 15 + 21 and 152 + 212 = 225 + 441 = 666 )
666^2 = (6 × 6 × 6)^2 + (666 - 6 × 6)^2
666 = \( {\displaystyle 2^{2}+3^{2}+5^{2}+7^{2}+11^{2}+13^{2}+17^{2}} \)
Second hexagonal numbers: a(n) = n*(2*n + 1).
666 = 36*37/2 Triangular number: a(n) = n*(n+1)/2
Palindromic in bases 4 and 10.
φ(666) = 6∙6∙6
Positive number whose product of digits is 12 times its sum.
The digits sum of the following powers is 666:
66647 = 5049969684420796753173148798405564772941516295265408188117632668936540446616033068653028889892718859670297563286219594665904733945856
66651 = 993540757591385940334263511341295980723858637469431008997120691313460713282967582530234558214918480960748972838900637634215694097683599029436416
666 = (1 + 1) × (1 + 1 + 1) × 111
666 = (2 + 2/2) × 222
666 = 3 × ((3 + 3)3 + 3 + 3)
666 = 444 × (4 + (4 + 4)/4)/4
666 = 555 + 555/5
666 = 777 − 777/7
666 = 888 × (8 − (8 + 8)/8)/8
666 = 9 × (9 × 9 − 9) + 9 + 9
666 (V)
Factors: 1, 2, 3, 6, 9, 18, 37, 74, 111, 222, 333, 666
Sqrt(666) = 25 + 1/(1 + 1/(4 + 1/(5 + 1/(1 + 1/(1 + 1/(6 + 1/(1 + 1/(4 + 1/(1 + 1/(6 + 1/(1 + 1/(1 + 1/(5 + 1/(4 + 1/(1 + 1/(50 + 1/...))))))))))))))))
Representations, Binary to Hexadecimal:
1010011010_2
220200_3
22122_4
10131_5
3030_6
1641_7
1232_8
820_9
556_11
476_12
3c3_13
358_14
2e6_15
29a_16
<--- --->
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
