1321

This number is a prime.

+ 1321 is an emirp and ((1321!)/(1231!))-1231 is prime. [Patterson]

+ π(1321) = 13 * 33 * 23 * 13. [Caldwell]

+ The smallest emirp that splits up into two consecutive Fibonacci numbers: 13, 21. Note that the digits consist of the first four nonzero Fibonacci numbers. [Beedassy]

+ A prime formed from first Fiboncacci numbers that can be expressed by first semiprimes raised to first primes: 4^5+6^3+9^2. [Silva]

(There are 2 curios for this number that have not yet been approved by an editor.)

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