diff --git a/Maths/SpyNumber.js b/Maths/SpyNumber.js
new file mode 100644
index 0000000000..753d294df4
--- /dev/null
+++ b/Maths/SpyNumber.js
@@ -0,0 +1,23 @@
+/**
+ * @function isSpyNumber
+ * @description A spy number is a number where the sum of its digits
+ *   equals the product of its digits.
+ *   For example, 1124: 1+1+2+4=8 and 1x1x2x4=8.
+ * @param {number} n - A positive integer
+ * @returns {boolean} - True if n is a spy number, false otherwise
+ * @see https://en.wikipedia.org/wiki/Spy_number
+ * @example isSpyNumber(1124) => true
+ * @example isSpyNumber(123) => true
+ * @example isSpyNumber(1234) => false
+ */
+const isSpyNumber = (n) => {
+  if (!Number.isInteger(n) || n < 1) {
+    throw new TypeError('Input must be a positive integer')
+  }
+  const digits = String(n).split('').map(Number)
+  const sum = digits.reduce((acc, d) => acc + d, 0)
+  const product = digits.reduce((acc, d) => acc * d, 1)
+  return sum === product
+}
+
+export { isSpyNumber }
diff --git a/Maths/test/SpyNumber.test.js b/Maths/test/SpyNumber.test.js
new file mode 100644
index 0000000000..ad38904023
--- /dev/null
+++ b/Maths/test/SpyNumber.test.js
@@ -0,0 +1,47 @@
+import { isSpyNumber } from '../SpyNumber.js'
+
+describe('isSpyNumber', () => {
+  test('1 is a spy number (1=1)', () => {
+    expect(isSpyNumber(1)).toBe(true)
+  })
+
+  test('123 is a spy number (1+2+3=6, 1x2x3=6)', () => {
+    expect(isSpyNumber(123)).toBe(true)
+  })
+
+  test('1124 is a spy number (1+1+2+4=8, 1x1x2x4=8)', () => {
+    expect(isSpyNumber(1124)).toBe(true)
+  })
+
+  test('132 is a spy number (1+3+2=6, 1x3x2=6)', () => {
+    expect(isSpyNumber(132)).toBe(true)
+  })
+
+  test('1234 is NOT a spy number (1+2+3+4=10, 1x2x3x4=24)', () => {
+    expect(isSpyNumber(1234)).toBe(false)
+  })
+
+  test('22 is NOT a spy number (2+2=4, 2x2=4) wait it is!', () => {
+    expect(isSpyNumber(22)).toBe(true)
+  })
+
+  test('12 is NOT a spy number (1+2=3, 1x2=2)', () => {
+    expect(isSpyNumber(12)).toBe(false)
+  })
+
+  test('11 is a spy number (1+1=2, 1x1=1) is false', () => {
+    expect(isSpyNumber(11)).toBe(false)
+  })
+
+  test('throws TypeError for zero', () => {
+    expect(() => isSpyNumber(0)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for negative input', () => {
+    expect(() => isSpyNumber(-123)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for float input', () => {
+    expect(() => isSpyNumber(1.5)).toThrow(TypeError)
+  })
+})