Improvements to a few Number APIs

files/en-us/web/javascript/reference/global_objects/number/isnan/index.md

@@ -36,12 +36,13 @@ Number.isNaN(value)
 
 ## Description
 
-Due to both equality operators, {{jsxref("Operators", "==",
-  "#Equality")}} and {{jsxref("Operators", "===", "#Identity")}},
+Due to both equality operators, [`==`](/en-US/docs/Web/JavaScript/Reference/Operators/Equality) and [`===`](/en-US/docs/Web/JavaScript/Reference/Operators/Strict_equality),
 evaluating to `false` when checking if {{jsxref("NaN")}} _is_
 {{jsxref("NaN")}}, the function `Number.isNaN()` has become necessary. This
 situation is unlike all other possible value comparisons in JavaScript.
 
+Since `x !== x` is only true for `NaN` among all possible JavaScript values, `Number.isNaN(x)` can also be replaced with a test for `x !== x`, despite the latter being less readable.
+
 In comparison to the global {{jsxref("isNaN", "isNaN()")}} function,
 `Number.isNaN()` doesn't suffer the problem of forcefully converting the
 parameter to a number. This means it is now safe to pass values that would normally

files/en-us/web/javascript/reference/global_objects/number/issafeinteger/index.md

@@ -16,6 +16,24 @@ provided value is a number that is a _safe integer_.
 
 {{EmbedInteractiveExample("pages/js/number-issafeinteger.html")}}
 
+## Syntax
+
+```js
+Number.isSafeInteger(testValue)
+```
+
+### Parameters
+
+- `testValue`
+  - : The value to be tested for being a safe integer.
+
+### Return value
+
+The boolean value `true` if the given value is a number that is a
+safe integer. Otherwise `false`.
+
+## Description
+
 A safe integer is an integer that
 
 - can be exactly represented as an IEEE-754 double precision number, and
@@ -29,7 +47,7 @@ represented in IEEE-754, but the integer `2^53 + 1` can't be
 directly represented in IEEE-754 but instead rounds to `2^53` under
 round-to-nearest and round-to-zero rounding. The safe integers consist of all integers
 from `-(2^53 - 1)` inclusive to `2^53 - 1`
-inclusive (± `9007199254740991` or ± 9,007,199,254,740,991).
+inclusive (± `9_007_199_254_740_991`).
 
 Handling values larger or smaller than \~9 quadrillion with full precision requires
 using an [arbitrary precision arithmetic library](https://en.wikipedia.org/wiki/Arbitrary-precision_arithmetic).
@@ -38,22 +56,6 @@ information on floating point representations of numbers.
 
 For larger integers, consider using the {{jsxref("BigInt")}} type.
 
-## Syntax
-
-```js
-Number.isSafeInteger(testValue)
-```
-
-### Parameters
-
-- `testValue`
-  - : The value to be tested for being a safe integer.
-
-### Return value
-
-The boolean value `true` if the given value is a number that is a
-safe integer. Otherwise `false`.
-
 ## Examples
 
 ### Using isSafeInteger

files/en-us/web/javascript/reference/global_objects/number/min_value/index.md

@@ -15,7 +15,9 @@ The **`Number.MIN_VALUE`** property represents the smallest positive numeric val
 
 ## Description
 
-`Number.MIN_VALUE` is the smallest positive number (not the most negative number) that can be represented within float precision — in other words, the number closest to 0. That's approximately `5E-324`. The ECMAScript spec doesn't define a precise value that implementations are required to support — instead the spec says, _"must be the smallest non-zero positive value that can actually be represented by the implementation"_. But in practice, its precise value in browsers and in Node.js is `2^-1074`.
+`Number.MIN_VALUE` is the smallest positive number (not the most negative number) that can be represented within float precision — in other words, the number closest to 0. The ECMAScript spec doesn't define a precise value that implementations are required to support — instead the spec says, _"must be the smallest non-zero positive value that can actually be represented by the implementation"_. This is because small IEEE-754 floating point numbers are [denormalized](https://en.wikipedia.org/wiki/Subnormal_number), but implementations are not required to support this representation, in which case `Number.MIN_VALUE` may be larger.
+
+In practice, its precise value in mainstream engines like V8 (used by Chrome, Edge, Node.js), SpiderMonkey (used by Firefox), and JavaScriptCore (used by Safari) is `2^-1074`, or `5E-324`.
 
 Because `MIN_VALUE` is a static property of {{jsxref("Number")}}, you always use it as `Number.MIN_VALUE`, rather than as a property of a {{jsxref("Number")}} object you created.