diff --git a/Project-Euler/Problem3.js b/Project-Euler/Problem3.js
new file mode 100644
index 0000000000..d870b80b46
--- /dev/null
+++ b/Project-Euler/Problem3.js
@@ -0,0 +1,20 @@
+// https://projecteuler.net/problem=3
+const problem = 600851475143
+
+const largestPrime = (num) => {
+  let newnumm = num
+  let largestFact = 0
+  let counter = 2
+  while (counter * counter <= newnumm) {
+    if (newnumm % counter === 0) {
+      newnumm = newnumm / counter
+    } else {
+      counter++
+    }
+  }
+  if (newnumm > largestFact) {
+    largestFact = newnumm
+  }
+  return largestFact
+}
+console.log(largestPrime(problem))