The second unique prime in hexadecimal (base 16).
Internationally renowned researcher Dr. Karen Rogers did a study of 241 profoundly gifted children in 1994-1995 during a postdoctoral fellowship. It was especially useful to parents who had observed developmental differences in their children but were unaware of what those differences may signify.
The smallest duodecimal prime: p = (x^12 + y^12 )/(x^4 + y^4 ). [Russo]
The system of equations: 2w + 3x + 5y + 7z = 11; 13w + 17x + 19y + 23z = 29; 31w + 37x + 41y + 43z = 47; 53w + 59x + 61y + 67z = 71; has four fractions as its solution, each of which has denominator 241. [Rupinski]
The smallest prime p such that the concatenation of p in base 10 down up to base 2 is prime. [Russo]
The smallest prime p such that p7 can be written as the sum of 7 consecutive primes. Note that 2 + 4 + 1 = 7. [Rivera]
The smallest prime value (out of 14) resulting from the ninedigital fraction equation (A/B)^C + (D/E)^F + (G/H)^I, where the letters A to I represent any combination of the nine digits 1 through 9. Note that (6/3)^5 + (8/4)^7 + (9/1)^2 and (6/3)^7 + (8/4)^5 + (9/1)^2 are the only two distinct solutions for 241. [De Geest]
241 is the only number m such that prime(m) = (m * (m)). [Firoozbakht]
This easy-to-remember member of a twin prime pair is pronounced, "two for one." Get it?
241 = prime(prime(2!!*4!!*1!!)). [Javadifar]
The largest known prime p such that the reversal of (p! + p) is prime. [Firoozbakht]
(There are 11 curios for this number that have not yet been approved by an editor.)