This number is a prime.
A deletable prime number that can be reduced to the left-truncatable prime 4632647 after deleting in order the following digits (counted from the right): 3(the 5th digit), 5(3rd), 1(13th), 6(11th), 8(5th), 7(3rd), 6(5th) and 2(7th). Note that by concatenating the deleted digits in reverse order, another prime is obtained: 26786153. Also note that all the deleted digits are on prime places in the respective primes. [Necula]