How to work with very large integers

Short answer

Ordinary numbers are exact only up to 2 to the power 53. For larger integers, use BigInt, which is written with the n suffix:

console.log(9007199254740993);
console.log(String(9007199254740993n));

Output:

9007199254740992
9007199254740993

Calculations

BigInt numbers support the usual operators, but both operands must be BigInt:

const big = 2n ** 64n;
 
console.log(big.toString());
console.log((big / 3n).toString());

Output:

18446744073709551616
6148914691236517205

From a string

Large ids often come as strings. BigInt() turns them into numbers without losing digits:

const id = BigInt('123456789012345678901');
 
console.log((id + 1n).toString());

Output:

123456789012345678902

Common mistake

You cannot mix BigInt and ordinary numbers in one operation. Convert one of them explicitly:

try {
  console.log(10n + 1);
} catch (error) {
  console.log(error.message);
}
 
console.log((10n + BigInt(1)).toString());

Output:

Cannot mix BigInt and other types, use explicit conversions
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