241
This number is a prime.
The second unique prime in hexadecimal (base 16).
The prime numbers are identified as N0241 in Sloane's original "Handbook of Integer Sequences."
The smallest prime p such that p plus the reversal of p equals a palindromic prime. [Luhn]
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 smallest non-palindromic prime which can be expressed as sum of a number and its reverse, i.e., 241 = 170 + 071. [Gupta]
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 radioisotope americium-241 is used in many smoke detectors.
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) = π(m * π(m)). [Firoozbakht]
The United States Supreme Court case Chesapeake & Ohio Railway Company v. Asa P. Carnahan can be found on Page 241 of Volume 241.
This easy-to-remember member of a twin prime pair is pronounced, "two for one." Get it?
241 = prime(prime(2!!*4!!*1!!)). [Javadifar]
There are 241 known numbers that cannot be written as the
sum of at most four tetrahedral
numbers. [Capelle]
The largest known prime p such that the reversal of (p! + p) is
prime. [Firoozbakht]
If A = 1, B = 2, C = 3, ... , Z = 26, then 'TWIN PRIME CONJECTURE' is a twin prime. [Homewood]
Washington D.C. schools chancellor Michelle Rhee once fired
241 teachers at the same time.
If A = 1, B = 2, C = 3, ... , Z = 26, then 'THE RIEMANN HYPOTHESIS' is prime. [Homewood]
The largest prime that can be represented as sum of three double-digit emirps, i.e., 71+73+97=241. [Loungrides]
Let U(0) = 0, U(1) = 1, U(n) = 3*U(n-1) + U(n-2) for
n>1, then 241 is the only known prime p such that p^2
divides U(p-(13|p)), where (13|p) is the Legendre symbol,
i.e., a Wall-Sun-Sun-type prime to this Lucas sequence. [Luen]
241 is the only known Lucas–Wieferich prime to (U, V) = (3, −1). [Lemmett]
241 = (22^2-2)/2. Can you find the next prime of form (t^2-2)/2, where t is a repdigit of form 2*(10^n-1)/9? [Honaker]
During the Terror, the Military Commission presided over by
Lenoir sentenced 241 people to death. Reference: Alfred
Lallié (1896) La justice révolutionnaire à Nantes et dans
la Loire-Inférieure. Nantes, B. Cier, p. xxvii. [Olry]
North America's highest mountain (Denali) is 241 feet lower than Mount Chimborazo. [Green]
241 athletes participated in the first international
Olympic Games held in modern history. [Orr]
The prime counting function π(241) = 53 uses the distinct-digit set {1, 2, 3, 4, 5} only, and 241 is the
smallest prime with this property. Note that π(53) = 2^4*1. [Worrom]
The bridge at San Juan de Gaztelugatxe transitions into a
narrow path that contains 241 steps.
The licence plate of the red and white Plymouth Fury in the John Carpenter horror movie "Christine" is CQB 241. [Olry]