kdt310722
diff --git a/‎src/number/format.ts
+21-1 b/‎src/number/format.ts
+21-1
diff --git a/‎src/number/types.ts
+3-1 b/‎src/number/types.ts
+3-1
@@ -1,9 +1,29 @@
-import type { FormatOptions, Numberish } from './types'
+import { rtrim } from '../string'
+import type { FormatOptions, NumberString, Numberish } from './types'
+
+export function convertExponentialToString(num: Numberish) {
+    const str = num.toString()
+
+    if (!str.includes('e')) {
+        return str as NumberString
+    }
+
+    if (!str.includes('e-')) {
+        return BigInt(num).toString() as NumberString
+    }
+
+    const [base, exp] = str.split('e-').map(Number)
+    const precision = base.toString().replace('.', '').length + exp
+
+    return rtrim(Number.parseFloat(str).toFixed(precision), '0') as NumberString
+}
 
 export function format(number: Numberish, options: FormatOptions = {}) {
     let leadingZerosCount = 0
     let { maximumFractionDigits = 4, groupFractionLeadingZeros = false } = options
 
+    number = convertExponentialToString(number)
+
     const { exactFractionWhenZero = true, maximumFractionLeadingZeros = maximumFractionDigits } = options
     const [integerPart, fractionPart = '0'] = String(number).split('.')
 
 
@@ -1,4 +1,6 @@
-export type Numberish = `${number}` | 'Infinity' | '-Infinity' | '+Infinity' | number | bigint
+export type NumberString = `${number}` | 'Infinity' | '-Infinity' | '+Infinity'
+
+export type Numberish = NumberString | number | bigint
 
 export interface FormatOptions extends Intl.NumberFormatOptions {
     locales?: string | string[]