my @input = <
  270
  541
  993
  649
  2010741
  1425172824437700148
>;

# for $*IN.lines>>.Int -> $n {
for @input -> $n {
  say "$n is prime." and next if $n.is-prime;

  my $lo = (^$n).reverse.first(*.is-prime);
  my $hi = ($n..*).first(*.is-prime);

  say "$lo < $n < $hi";
}