# 41 (number)

(Redirected from Forty-one)
 ← 40 41 42 →
Cardinal forty-one
Ordinal 41st
(forty-first)
Factorization prime
Divisors 1, 41
Roman numeral XLI
Binary 1010012
Ternary 11123
Quaternary 2214
Quinary 1315
Senary 1056
Octal 518
Duodecimal 3512
Vigesimal 2120
Base 36 1536

41 (forty-one) is the natural number following 40 and preceding 42.

## In mathematics

Forty-one is the 13th smallest prime number. The next is forty-three, with which it comprises a twin prime. It is also the sum of the first six prime numbers (2 + 3 + 5 + 7 + 11 + 13), and the sum of three primes (11 + 13 + 17).

Forty-one is also the 12th supersingular prime, a Sophie Germain prime and a Newman–Shanks–Williams prime. 41 is the smallest Sophie Germain prime to start a Cunningham chain of the first kind of three terms, {41, 83, 167}. It is an Eisenstein prime, with no imaginary part and real part of the form 3n − 1. 41 is a Proth prime as it is  5 × 23 + 1.

The number figures in the polynomial f(n) = n2 + n + 41, which yields primes for −40 ≤ n < 40. This is also called the lucky number of Euler Prime. It is the biggest of such primes.

Forty-one is the sum of two squares, 42 + 52. Adding up the sums of divisors for 1 through 7 yields 41.

41 is the smallest integer whose reciprocal has a 5-digit repetend. That is a consequence of the fact that 41 is a factor of 99999.

It is a centered square number.

## References

1. ^ "41 (II)". IMDB. Retrieved June 16, 2013.
2. ^ Boyd, M. J. "The African American Presence and the Resolution of Race in The Matrix Trilogy." Black Renaissance. 3 (2004): 134
3. ^ Telegraph.co.uk
4. ^ [1]
5. ^ Kellogg, William O. (2010). Barron's AP United States History (9th ed.). Barron's Educational Series. p. 364. ISBN 9780764141843. George H. W. Bush (Republican) [Bush 41—i.e., the first president Bush, George H. W. Bush was the forty-first President of the United States, and so some have referred to him in this way since the election of his son, George W. Bush or Bush 43—the forty-third president of the United States.]
6. ^ Reference 1
7. ^ Reference 2
8. ^ [2]