241 (number)

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← 240 241 242 →
Cardinal two hundred forty-one
Ordinal 241st
(two hundred forty-first)
Factorization prime
Prime twin prime
Roman numeral CCXLI
Binary 111100012
Ternary 222213
Quaternary 33014
Quinary 14315
Senary 10416
Octal 3618
Duodecimal 18112
Hexadecimal F116
Vigesimal C120
Base 36 6P36

241 (two hundred [and] forty-one) is the natural number between 240 and 242. It is also a prime number.

In mathematics[edit]

241 is the larger of the twin primes (239, 241). Twin primes are pairs of primes separated by 2.

241 is a regular prime[1] and a lucky prime.[2]

Since 241 = 15 × 24 + 1, it is a Proth prime.

241 is a repdigit in base 15 (111).

241 is the only known Lucas–Wieferich prime to (U, V) = (3, −1).

In Chemistry[edit]

Americium-241 is the most common isotope of Americium, used in smoke detectors.

In popular culture[edit]

  • Reel Big Fish wrote a song entitled "241," where the number is repeated as the only lyric.
  • A short form of the phrase "Two for One" describing a discount.
  • Made popular by Gil Harrington following the abduction and murder of her daughter Morgan Harrington. "241" was shared between the family, meaning, "I love you too much, forever, and one more time." It is a symbol of everlasting and unrelinquishing love for one another.[citation needed]


  1. ^ "Sloane's A007703 : Regular primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28. 
  2. ^ "Sloane's A031157 : Numbers that are both lucky and prime". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.