# 241 (number)

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

241 is the natural number between 240 and 242. It is also a prime number.

## In mathematics

241 is the larger of the twin primes (239, 241).
Prime twins are always of the form (6n - 1, 6n + 1), with n = 1, 2, 3, ... [Thus the set of smallest twin primes is (5, 7).]

241 is a regular prime and a lucky prime.

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

241 is a repdigit in base 15 (111).

## In Chemistry

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

## In popular culture

• 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.

## In professional sports

The seating Section 241 of Nationals Park, the home of the Washington Nationals Major League Baseball team, is known as the National League's rowdiest seating areas, if not the rowdiest in all of baseball.

Fans seated in Section 241, generally single young professionals between the ages of 18 and 35, typically chant "two-four-one! two-four-one!" and often attempt to start the wave. The former has been thought to distract and perplex outfielders of visiting teams.

The section's unique persona is believed to be rooted in the number 241. Regulars of the section are believed to have chosen it because 241, pronounced "two-four-one" sounds similar to the name of the two-for-one special sales of beer at the ballpark.