22

This number is a composite.

Just showing those entries submitted by 'Russo': (Click here to show all)

The smallest integer such that its sum of digits ± 1 and the product of its digits is prime, together with the fact that the sum of digits is the same as the product. [Russo]

The smallest multi-digit square-free number such that all the digits are primes. [Russo]

The smallest multi-digit composite palindrome whose total number of prime factors (counting multiplicity) is square-free. [Russo]