5781 = 1 × 23 + 45 + 6 × 789
5781 = (9 × 8 + 7 + 6 + 5) × 43 + 21
5781 = 0^6 − 1^8 + 2^9 + 3^7 + 4^5 + 5^2 + 6^4 + 7^0 + 8^1 + 9^3
5781 divides 46^20 - 1.
9-gonal (or enneagonal or nonagonal) numbers: a(n) = n*(7*n-5)/2, n = 41
Sum of three consecutive pentagonal numbers.
Sphenic number: Product of 3 distinct Primes, (List)
Factors: 1, 3, 41, 47, 123, 141, 1927, 5781
Representations, Binary to Hexadecimal:
1011010010101_2
21221010_3
1122111_4
141111_5
42433_6
22566_7
13225_8
7833_9
4386_11
3419_12
2829_13
216d_14
1aa6_15
1695_16
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Undergraduate Texts in Mathematics
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