66 = 1 × 23 + 4 + 5 × 6 + 7 + 8 + 9
66 = 9 + 8 + 7 + 6 + (5 + 4 + 3) × (2 + 1)
66 = 0^4 − 1^8 − 2^6 − 3^9 + 4^7 + 5^5 + 6^3 + 7^1 + 8^0 + 9^2
66 = 11 × (1 + 1) × (1 + 1 + 1)
= 2(2+2+2) + 2
= 33 + 33
= (44 + 4 + 4)/4
= 55 + 55/5
= 66
= 77 − 77/7
= 8 × 8 + (8 + 8)/8
= 99 × (99 + 9)/(9 × (9 + 9))
66 = (11 × 12) /2, Triangular number
Number that is the sum of 4 positive 5th powers.
Sphenic number: Product of 3 distinct Primes, (List)
Numbers k such that 2^k + 9 is prime
Number of points on surface of octahedron; also coordination sequence for cubic lattice: a(0) = 1; for n > 0, a(n) = 4n^2 + 2. n=4
Positive number whose product of digits is three times their sum.
Factors: 1, 2, 3, 6, 11, 22, 33, 66
Representations, Binary to Hexadecimal:
1000010_2
2110_3
1002_4
231_5
150_6
123_7
102_8
73_9
60_11
56_12
51_13
4a_14
46_15
42_16
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Graduate Studies in Mathematics
