919
This number is a prime.
The smaller number in the smallest pair of prime numbers that are mutually the sums of (the same) powers of each other's digits, i.e., 919 = 13 + 43 + 53+ 93 and 1459 = 93+ 13 + 93. [Hartley]
The smallest multidigit palindromic prime whose sum of digits shows up as a substring of the prime. [Russo]
The smallest number that cannot be added to a nonzero palindrome such that the sum is also palindromic. [De Geest]
The deepest and steepest depression prime. [Punches]
A palindromic prime containing nineteen letters in its English name "nine hundred nineteen." Note that 9 + 1 + 9 equals nineteen and you get nineteen in either direction (left or right) from the center. [Post]
This prime is the 18th centered hexagonal number. Note that we can use the digits of 919 to write 18 = (9 * 1) + 9 = 9 + (1 * 9). [Post]
According to the Australian Bureau Of Meteorology, the prime number 919 millimetres is the record high mean annual rainfall over the State Of Victoria. Note that the year in which this occurred (1973) is also prime!
Modern studies have shown that the earliest known version of the beast number (666) may have been 919 turned upside down.
The largest known palindromic prime for which the next prime is also palindromic. [Beedassy]
The smallest multidigit palindromic cuban prime. Note that it ends with the smallest multidigit cuban prime (19) and begins with its reversal (91). [Capelle]
The smallest palindromic prime equal to the difference of consecutive cubes (18^3-17^3). [Silva]
The sum of the digits of first non-trivial palindromic primes up to 919 is another palindromic prime. [Silva]
The smallest prime whose nearest neighbors have the same number of divisors, the same number of distinct prime factors, and the same sum of divisors. [Rush]
The smallest palindromic prime which has a multiplicative persistence of two. [Wesolowski]
919 equals 91+81+71+61+51+41+31+21+11+1+11+21+31+41+51+61+71+81+91. [Silva]
The only prime less than a googol of form 91k9. [Loungrides]
The smallest prime formed by concatenating in ascending order the first n consecutive numbers ending with 9, (n=2). The next such prime is for n=26. [Loungrides]
The hundredth palindrome and 19th prime palindrome. [Gaydos]
Modern Galápagos tortoises can weigh up to 919 lb. [Davis]
The 19th palindromic prime ending in 19 with sum of digits as 19. [Gupta]
There are 919 distinct-digit triangular numbers including zero. [Gaydos]
919 is the sum of a semiprime number of consecutive semiprimes:221+226+235+237. Curiously 919 results from de projection of a semiprime. [Silva]
The Comac C919 is a narrow-body airliner developed by Chinese aircraft manufacturer Comac. [Lee]
The largest prime number in Beale's first cryptogram. [Cole]