Primes impl with streams

Primes.java

import static java.lang.Math.sqrt;
import static java.util.stream.IntStream.range;
import static java.util.stream.IntStream.rangeClosed;

public class Primes {

  public boolean isPrime(int n) {
    return n > 1 && !rangeClosed(2, (int) sqrt(n)).anyMatch(d -> n % d == 0);
  }

  public int numberOfPrimesBelow(int limit) {
    return (int) range(2, limit).filter(this::isPrime).count();
  }

  public int numberOfTwinPrimePairsBelow(int limit) {
    return (int) range(2, limit)
      .filter(n -> isPrime(n) && isPrime(n + 2))
      .count();
  }

  public boolean isSuperPrime(int n) {
    return isPrime(n) && isPrime(numberOfPrimesBelow(n) + 1);
  }
}