# The Number isSafeInteger() method

Find out all about the JavaScript isSafeInteger() method of the Number object

A number might satisfy `Number.isInteger()` but not `Number.isSafeInteger()` if it goes out of the boundaries of safe integers, which I explained above.

So, anything over `2^53` and below `-2^53` is not safe:

``````Number.isSafeInteger(Math.pow(2, 53)) // false
Number.isSafeInteger(Math.pow(2, 53) - 1) // true
Number.isSafeInteger(Math.pow(2, 53) + 1) // false
Number.isSafeInteger(-Math.pow(2, 53)) // false
Number.isSafeInteger(-Math.pow(2, 53) - 1) // false
Number.isSafeInteger(-Math.pow(2, 53) + 1) // true``````

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