213 = 1 + 2 × 34 + 5 + 67 + 8 × 9
213 = 9 + 8 + 76 + 5 × 4 × 3 × 2 × 1
213 = 0^5 + 1^8 − 2^7 − 3^9 + 4^1 + 5^6 + 6^3 + 7^0 + 8^4 + 9^2
213 divides 70^2 - 1.
213 = (1 + 1) × (111 + 1) − 11
213 = 222 + 2 − 22/2
213 = (3 + 3)3 − 3
213 = 44 − 44 + 4/4
213 = (55 − 5)/(5 + 5 + 5) + 5
213 = 6 × 6 × 6 − 6 × 6/(6 + 6)
213 = 7 × (7 + 7 + 7) + 77 − 77/7
213 = 88 + 8 × (8 + 8) + 8 − 88/8
213 = (9 + 9) × (9 + 9) − 999/9
Pendulum number: alternately append n to beginning or end of previous term.
Semiprime (Product of 2 Primes)
Number k such that k, k+2, k+4, k+6, k+8 are semiprimes.
Number of fractions in Farey series of order 26 : 0/1, 1/26, 1/25, 1/24, 1/23, 1/22, 1/21, 1/20, 1/19, 1/18, 1/17, 1/16, 1/15, 1/14, 1/13, 2/25, 1/12, 2/23, 1/11, 2/21, 1/10, 2/19, 1/9, 3/26, 2/17, 3/25, 1/8, 3/23, 2/15, 3/22, 1/7, 3/20, 2/13, 3/19, 4/25, 1/6, 4/23, 3/17, 2/11, 3/16, 4/21, 5/26, 1/5, 5/24, 4/19, 3/14, 5/23, 2/9, 5/22, 3/13, 4/17, 5/21, 6/25, 1/4, 6/23, 5/19, 4/15, 7/26, 3/11, 5/18, 7/25, 2/7, 7/24, 5/17, 3/10, 7/23, 4/13, 5/16, 6/19, 7/22, 8/25, 1/3, 9/26, 8/23, 7/20, 6/17, 5/14, 9/25, 4/11, 7/19, 3/8, 8/21, 5/13, 7/18, 9/23, 2/5, 9/22, 7/17, 5/12, 8/19, 11/26, 3/7, 10/23, 7/16, 11/25, 4/9, 9/20, 5/11, 11/24, 6/13, 7/15, 8/17, 9/19, 10/21, 11/23, 12/25, 1/2, 13/25, 12/23, 11/21, 10/19, 9/17, 8/15, 7/13, 13/24, 6/11, 11/20, 5/9, 14/25, 9/16, 13/23, 4/7, 15/26, 11/19, 7/12, 10/17, 13/22, 3/5, 14/23, 11/18, 8/13, 13/21, 5/8, 12/19, 7/11, 16/25, 9/14, 11/17, 13/20, 15/23, 17/26, 2/3, 17/25, 15/22, 13/19, 11/16, 9/13, 16/23, 7/10, 12/17, 17/24, 5/7, 18/25, 13/18, 8/11, 19/26, 11/15, 14/19, 17/23, 3/4, 19/25, 16/21, 13/17, 10/13, 17/22, 7/9, 18/23, 11/14, 15/19, 19/24, 4/5, 21/26, 17/21, 13/16, 9/11, 14/17, 19/23, 5/6, 21/25, 16/19, 11/13, 17/20, 6/7, 19/22, 13/15, 20/23, 7/8, 22/25, 15/17, 23/26, 8/9, 17/19, 9/10, 19/21, 10/11, 21/23, 11/12, 23/25, 12/13, 13/14, 14/15, 15/16, 16/17, 17/18, 18/19, 19/20, 20/21, 21/22, 22/23, 23/24, 24/25, 25/26, 1/1
Semiprime (Product of 2 Primes)
Factors: 1, 3, 71, 213
Two hundred thirteen
Representations, Binary to Hexadecimal:
11010101_2
21220_3
3111_4
1323_5
553_6
423_7
325_8
256_9
184_11
159_12
135_13
113_14
e3_15
d5_16
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