diff --git a/Math/Number/Integer.php b/Math/Number/Integer.php
index 884bfd717..594d1ad99 100644
--- a/Math/Number/Integer.php
+++ b/Math/Number/Integer.php
@@ -1,9 +1,87 @@
-class Integer implements Number {
-public function isPrime() {
+<?php
+class Integer implements Number 
+{
+	public static function isInteger($value) : bool
+	{
+		return is_int($value);
+	}
 
-}
+	/**
+     * Greatest common diviser.
+     *
+     * @param int $n Number one
+     * @param int $m Number two
+     *
+     * @return int
+     *
+     * @since  1.0.0
+     * @author Dennis Eichhorn
+     */
+    public static function greatestCommonDivisor(int $n, int $m) : int
+    {
+        while (true) {
+            if ($n === $m) {
+                return $m;
+            } if ($n > $m) {
+                $n -= $m;
+            } else {
+                $m -= $n;
+            }
+        }
+    }
 
-public function getIntegerFactorization() {
+	public static function trialFactorization(int $value) 
+	{
+		if ($value < 2) {
+			return [];
+		}
 
-}
+		$factors = [];
+		$primes = Prime::sieveOfEratosthenes((int) $value**0.5);
+
+		for($primes as $prime) {
+			if($prime*$prime > $value) {
+				break;
+			}
+
+			while($value%$prime === 0) {
+				$factors[] = $prime;
+				$value /= $prime; 
+			}
+		}
+
+		if($value > 1) {
+			$factors[] = $value;
+		}
+
+		return $factors;
+	}
+
+	public static function pollardsRho($value, $x = 2, $factor = 1, $cycleSize = 2, $xFixed = 2) 
+	{
+		while($factor === 1) {
+			for($i = 1; $i < $cycleSize && $factor <= 1; $i++) {
+				$x = ($x*$x+1)%$value;
+				$factor = self::greatestCommonDivisor($x-$xFixed, $value);
+			}
+
+			$cycleSize *= 2;
+			$xFixed = $x;
+		}
+
+		return $factor;
+	}
+
+	public static function fermatFactor(int $value)
+	{
+		$a = $value;
+		$b2 = $a*$a - $value;
+
+		while(abs((int) round(sqrt($b2), 0) - sqrt($b2)) > 0.0001) {
+			$a += 1;
+			$b2 = $a*$a - $value;
+		}
+
+		return $a - sqrt($b2);
+	}
 }
\ No newline at end of file
diff --git a/Math/Number/Natural.php b/Math/Number/Natural.php
index ce1b72ba3..7e34819ad 100644
--- a/Math/Number/Natural.php
+++ b/Math/Number/Natural.php
@@ -1,2 +1,9 @@
-class Natural implements Number {
+<?php
+
+class Natural implements Number 
+{
+	public static function isNatural($value) : bool
+	{
+		return is_int($value) && $value >= 0;
+	}
 }
\ No newline at end of file
diff --git a/Math/Number/Numbers.php b/Math/Number/Numbers.php
index 13330171d..bf8b1c8b2 100644
--- a/Math/Number/Numbers.php
+++ b/Math/Number/Numbers.php
@@ -142,28 +142,4 @@ class Numbers
 
         return $count;
     }
-
-    /**
-     * Greatest common diviser.
-     *
-     * @param int $n Number one
-     * @param int $m Number two
-     *
-     * @return int
-     *
-     * @since  1.0.0
-     * @author Dennis Eichhorn
-     */
-    public static function greatestCommonDivisor(int $n, int $m) : int
-    {
-        while (true) {
-            if ($n === $m) {
-                return $m;
-            } if ($n > $m) {
-                $n -= $m;
-            } else {
-                $m -= $n;
-            }
-        }
-    }
 }
\ No newline at end of file
diff --git a/Math/Number/Prime.php b/Math/Number/Prime.php
index 7a8161289..6ddf2846b 100644
--- a/Math/Number/Prime.php
+++ b/Math/Number/Prime.php
@@ -116,4 +116,45 @@ class Prime
 
         return true;
     }
+
+    public static function sieveOfEratosthenes(int $n) : array
+    {
+        $number = 2;
+        $range = range(2, $n);
+        $primes = array_combine($range, $range);
+         
+        while ($number*$number < $n) {
+            for ($i = $number; $i <= $n; $i += $number) {
+                if ($i == $number) {
+                    continue;
+                }
+
+                unset($primes[$i]);
+            }
+
+            $number = next($primes);
+        }
+
+        return $primes;
+    }
+
+    public function isPrime(int $n) : bool
+    {
+        $i = 2;
+     
+        if ($n === 2) {
+            return true; 
+        }
+     
+        $sqrtN = sqrt($n);
+        while ($i <= $sqrtN) {
+            if ($n % $i === 0) {
+                return false;
+            }
+
+            $i++;
+        }
+     
+        return true;
+    }
 }
\ No newline at end of file