# 383

This number is a prime.

The only known multidigit palindromic Woodall prime.

Sexy primes are such that *n* and *n* + 6 are both prime. The pair (383, 389) for example.

The first multidigit palindromic prime to appear in the decimal expansion of π. [Wu]

The sum of the first three 3-digit palindromic primes. [Vouzaxakis]

383 is the smallest p(n) such that the continued fraction expansion of [p(n)+sqrt(p(n+1))]/p(n+2) has a prime number of coefficients in its periodic portion. [Rupinski]

The smallest prime which can be represented as sum of a prime and its reversal (241 + 142 = 383). [Gupta]

383 = 6*2^6 - 1. [Noll]

The smallest palindromic Pillai prime.

Together with 191, this prime forms a palindromic Sophie Germain pair: i.e., 2(191)+1 = 383. Less known is the fact that 383 divides the Mersenne number 2^191-1. [De Geest]

383 = prime(3*8*3) + sigma(3+8+3). Note that 383 is the earliest number (coincidentally prime) with this property. [Firoozbakht]

The smallest prime of the form 383*2^n+1 is titanic.

The product of the nonzero even digits minus 1. [Silva]

An aqueous solution of hydrochloric acid boils at a higher temperature than pure water and reaches a maximum boiling (or azeotropic) point of 383 K. [Beedassy]

The sum of three consecutive balanced primes (53 + 157 + 173). [Silva]

383 = 3^5 + 1^4 + 4^1 + 1^9 + 5^3 + 9^1. Note the first six digits of the decimal expansion of π as bases and exponents. [Silva]

The ordered concatenation of all reflectable primes up to 383 is a reflectable prime. Can you find a larger example?

In the movie "Superman II," 383 is Otis' and Lex Luthor's prison cell number.

The smallest palindromic curved-digit-prime. [Bajpai]

The largest prime in the binary sequence 101, 1011, 10111..., 101111111. The only one which is not prime is, ironically, the 7 digit 1011111 with 5 consecutive ones. [Homewood]

383 is the only palindromic “almost evenian prime” less than a googol, i.e., a prime that can be represented as the product of first n positive even numbers minus 1, (case n=4), i.e., 2*4*6*8-1 = 383. [Loungrides]

1966322 has a Collatz trajectory length of 383 and its largest prime factor is 383. Are there any larger examples of this property? [Gaydos]

Difference in the number of digits of Mersenne prime M22 (i.e., 2993) and the number of digits of its immediate successor M23 (i.e., 3376). [Harrison]

David Darling's *The Universal Book of Mathematics* is a 383-page book. [Olry]

Nolan Ryan holds the Major League Baseball single-season strikeout record at 383. [Enberg]

The smallest n-digit palindromic prime that is the sum of n consecutive n-digit palindromic primes, i.e., (101 + 131 + 151), (case n=3). [Bajpai]

The first three consecutive nonpalindromic balanced primes sum to give the (3+8+3)th palindromic prime 383. Note that these three primes form a prime palindromic set {3, 5, 17, 71, 5, 3}. [Worrom]