Added BigInt support and did some refactoring

src/algorithms/math/is-power-of-two/isPowerOfTwo.js

@@ -1,24 +1,37 @@
 /**
- * @param {number} number
+ * @param {number|bigint} numeric value to check
  * @return {boolean}
  */
-export default function isPowerOfTwo(number) {
+export default function isPowerOfTwo(x) {
   // 1 (2^0) is the smallest power of two.
-  if (number < 1) {
-    return false;
+  if (x <= 1) {
+    return x == 1;
+  }
+
+  // guard clause to dispatch BigInts ASAP
+  if (typeof x == "bigint") {
+    // the bitwise alt works for any BigInt
+    // because bit operators are arbitrary-precision for them
+    return (x & (x - 1n)) === 0n;
   }
 
   // Let's find out if we can divide the number by two
   // many times without remainder.
-  let dividedNumber = number;
-  while (dividedNumber !== 1) {
-    if (dividedNumber % 2 !== 0) {
-      // For every case when remainder isn't zero we can say that this number
-      // couldn't be a result of power of two.
+  let dividedNum = x / 2;
+  while (dividedNum !== 1) {
+    if ( !Number.isInteger(dividedNum) ) {
+      /*
+      For every case when quotient is non-int we can say that this number
+      couldn't be a result of power of two (with integer exponent),
+      because checking the fractional part of a quotient is equivalent to checking if the remainder is 0,
+      and the remainder is the value of the least significant bit (with fractional part included).
+      All powers of 2 (but `1`) must have consecutive trailing zeros.
+      this also immediately dispatches non-int values of `x`, because neither rem nor quotient is an int
+      */
       return false;
     }
 
-    dividedNumber /= 2;
+    dividedNum /= 2;
   }
 
   return true;