3221
This number is a prime.
The smallest prime (emirp) formed by concatenating the sum and the product of digits of a number n, with the number n, (case n=21). Shall we call 3221 an SPn prime? [Loungrides]
The smallest emirp with a partition into three consecutive
emirps (1061 + 1069 + 1091) that concatenate to a prime
(106110691091). Note that the latter nonprime-digit prime
derives from a noncomposite-digit emirp. [Beedassy]
(There is one curio for this number that has not yet been approved by an editor.)
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