Number.MAX_SAFE_INTEGER

The Number.MAX_SAFE_INTEGER static data property represents the maximum safe integer in JavaScript (253 – 1).

Double precision floating point format only has 52 bits to represent the mantissa, so it can only safely represent integers between -(253 – 1) and 253 – 1. “Safe” in this context refers to the ability to represent integers exactly and to compare them correctly. For example, Number.MAX_SAFE_INTEGER + 1 === Number.MAX_SAFE_INTEGER + 2 will evaluate to true, which is mathematically incorrect. See Number.isSafeInteger() for more information.

As mentioned in Number.EPSILON, the precision of numbers depends on their magnitude. Number.MAX_SAFE_INTEGER represents the largest value at which integer-level operations can be performed precisely, but you can still perform meaningful arithmetic on numbers larger than that, just without integer-level precision. The largest representable number in JavaScript is actually Number.MAX_VALUE, which is approximately 1.7976931348623157 × 10308.