This number is a prime.

+ Observing that 521, M(521), 953, 61, and M(61) are prime, it is curious that 521*2^953+61 is also prime. [Noll]

+ The first emirp p such that 2p+1 and 3p+2 are prime. [Loungrides]

+ The largest three-digit centered heptagonal number. [Homewood]

+ The smallest emirp p such that prime(p)*p + π(p) yields another emirp. [Bajpai]

(There are 3 curios for this number that have not yet been approved by an editor.)

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