1609

This number is a prime.

The nearest whole number of meters in a mile is prime. [Wu]

The house at 1609 16th St. NW in Washington, D.C. (H. Cornell Wilson House) was the home/office of the Einstein-like scientist Dr. Barnhardt in the classic movie The Day the Earth Stood Still. [McCranie]

The year Galileo turned a telescope to the sky, and turned man's view of the world upside down. Note that 1609 turned upside down gives another prime, making 1609 an invertible prime. [Teague]

The largest invertible prime to appear in the first 1000 digits of e, starting at the digit 833. [Gupta]

The smallest prime number formed from the leading digits of the natural logarithm of the first composite number. [Gudipati]

(1609, 1613) is the first case of a 4-digit cousin prime pair (p, q) such that p^2+q^3 -/+ 1 is a twin prime pair, i.e., 1609^2+1613^3-1= 4199242277 and 1609^2+1613^3+1= 4199242279 are both prime. [Loungrides]

Danish astronomer Tycho Brahe announced his first two laws in the year 1609. [Upadhyay]

The sum of exponents of the first fourteen Mersenne primes. [Harrison]

The only prime whose reversal is a 2-sphenic number, i.e., 9061 = 13 x 17 x 41. [Loungrides]

The reversal of 1609 is the 1609th sphenic number. [Gaydos]