7331
This number is a prime.
 The smallest prime whose conversion from seconds into hours, minutes, and seconds, gives a prime number of hours, minutes, and seconds (7331s = 2h 2m 11s).  [Thoms]
 
The smallest prime whose conversion from seconds into hours, minutes, and seconds, gives a prime number of hours, minutes, and seconds (7331s = 2h 2m 11s).  [Thoms]
 The larger of only two right-truncatable primes formed by concatenating two double-digit right-truncatable emirps. The other is 3137.  [Loungrides]
 
The larger of only two right-truncatable primes formed by concatenating two double-digit right-truncatable emirps. The other is 3137.  [Loungrides]
 The largest of only three right-truncatable primes, each formed by concatenating two double-digit emirps. The other two are 3137 and 3797. Note that 7331 is the only right-truncatable prime concatenated in descending order from two double-digit emirps.  [Loungrides]
 
The largest of only three right-truncatable primes, each formed by concatenating two double-digit emirps. The other two are 3137 and 3797. Note that 7331 is the only right-truncatable prime concatenated in descending order from two double-digit emirps.  [Loungrides]
 The only prime concatenated from two double-digit primes p, g whose first prime is the 73.  [Loungrides]
 
The only prime concatenated from two double-digit primes p, g whose first prime is the 73.  [Loungrides]
 7331, 73331, 733331 and 7333331 are all prime numbers.  [Anitha]
 
7331, 73331, 733331 and 7333331 are all prime numbers.  [Anitha]