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 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 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]
(There is one curio for this number that has not yet been approved by an editor.)
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