1491 = 1 × 2 × (345 + 6) + 789
1491 = 98 × (7 + 6) + 5 × 43 + 2 × 1
1491 = 0^7 + 1^8 − 2^4 − 3^9 + 4^6 + 5^1 + 6^3 + 7^5 + 8^2 + 9^0
1491 divides 76^10 - 1.
9-gonal (or enneagonal or nonagonal) numbers: a(n) = n*(7*n-5)/2, n = 21
Sphenic number: Product of 3 distinct Primes, (List)
Factors: 1, 3, 7, 21, 71, 213, 497, 1491
Representations, Binary to Hexadecimal:
10111010011_2
2001020_3
113103_4
21431_5
10523_6
4230_7
2723_8
2036_9
1136_11
a43_12
8a9_13
787_14
696_15
5d3_16
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Undergraduate Texts in Mathematics
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