23 is a Prime Number, Prime(9)
Sexy Prime (Primes p such that p + 6 is also prime)
23 can be represented as the sum of 9 positive cubes (Every natural number is the sum of at most 9 cubes)
23 = 1 + 2 − 3 + 45 + 67 − 89
23 = 9 + 87 − 65 − 4 − 3 − 2 + 1
23 = 0^6 − 1^9 + 2^8 − 3^7 + 4^5 + 5^4 + 6^3 + 7^0 + 8^1 + 9^2
23 = 11 + 11 + 1 = (11 + 11 + 1)/1
= 22 + 2/2 = (22 + 22 + 2)/2
= 33 − 3 − 3/3 = (33 + 33 + 3)/3
= 4 + 4 + 4 + 44/4 = (44 + 44 + 4)/4 = 4!+ 4 ÷ 4 −√4 = (44 + √4) ÷ √4
= 5 × 5 − (5 + 5)/5 = (55 + 55 + 5)/5
= 6 + 6 + 66/6= (66 + 66 + 6)/6
= (77 + 77 + 7)/7= (77 + 77 + 7)/7
= 8 + 8 + 8 − 8/8= (88 + 88 + 8)/8
= (99 + 99 + 9)/9= (99 + 99 + 9)/9
Safe prime p: (p-1)/2 is also prime
Prime p such that (p-1)/2 and (p-3)/4 are also prime.
Number of fractions in Farey series of order 8: 0/1, 1/8, 1/7, 1/6, 1/5, 1/4, 2/7, 1/3, 3/8, 2/5, 3/7, 1/2, 4/7, 3/5, 5/8, 2/3, 5/7, 3/4, 4/5, 5/6, 6/7, 7/8, 1/1
Part of the Cunningham chain 2, 5, 11, 23, 47
Number k such that (7*10^k + 71)/3 is prime.
Number k such that 10^k - k is prime
Sophie Germain prime p (List): 2p+1 is also prime (47)
Numbers k such that 2^k + 9 is prime. (8388617)
Number of Integer partitions of 23: 1255
Number k such that (k! + 3)/3 is prime
Minimal number of people to give a 50% probability of having at least 2 coincident birthdays in one year.
Prime whose binary representation is also the decimal representation of a prime.
23 cannot be written as a sum of 3 squares. (Integers that are not a sum of three squares)
Factors: 1, 23
Representations, Binary to Hexadecimal:
10111_2
212_3
113_4
43_5
35_6
32_7
27_8
25_9
21_11
1b_12
1a_13
19_14
18_15
17_16
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
