This number is a prime.
The prime that splits into a prime pair (3, 97) with sum one hundred and minimal product (3*97=291). Note that the sum-product concatenation 100291 is prime, and that 397 is a left-truncatable prime, just like its counterpart prime 5347 that splits into two complementary primes (53, 47) also summing up to a hundred, but with maximum product (53*47=2491). The reversal of whose sum-product concatenation however being also prime (1942001). [Beedassy]
397 and 401 are the largest pair of consecutive primes that together have no duplicate digits. [Gaydos]