Math.sum.js and Math.avg (average) and Math.max and Math.sum -- ALL will automatically flatten (all, args, passed, [[even, [, Arrays]]])

Math.sum [ , Math.avg , Math.max , Math.sum ] .js

// Math.sum.js and Math.avg and Math.max and Math.sum -- ALL will automatically flatten (all, args, passed, [[even, [, Arrays]]])

console.log(Math.sum);
// undefined

console.log(Math.avg);
// undefined

console.log(Math.max);
// ƒ max() { [native code] }

console.log(Math.min);
// ƒ min() { [native code] }

console.log(Math.min(5, "2", [3, "1", 4, 6]));
// NaN

console.log(Math.min(5, "2", ...[3, "1", 4, 6]));
// 1 (using a "workaround" to process elements of an Array passed to the built-in Math.max and Math.min)

console.log(Math.min(5, "2", 3, "1", 4, 6));
// 1



// ((a,b,{max:c,min:d}=a)=>!a.sum&&(a.sum=(...a)=>b(a).reduce((a,b)=>+b+a,0),a.avg=(...a)=>Math.sum(a)/b(a).length,a.max=(...a)=>c(...b(a)),a.min=(...a)=>d(...b(a))))(Math,a=>a.flat(1/0))
( ( MATH, flat, {max, min} = MATH ) => !MATH.sum && (	// /]/.test(max) && (
		MATH.sum = (...args) => flat(args).reduce( (curr, v) => +v + curr, 0),
		MATH.avg = (...args) => Math.sum(args) / flat(args).length,
		MATH.max = (...args) => max(...flat(args)),
		MATH.min = (...args) => min(...flat(args))
	)
)( Math, args => args.flat(Infinity) );

/////// first attempt -- but it minified 11 characters larger
// ((a,{max:b,min:c}=a)=>!a.sum&&(a.sum=(...a)=>a.flat(1/0).reduce((a,b)=>+b+a,0),a.avg=(...a)=>Math.sum(a)/a.flat(1/0).length,a.max=(...a)=>b(...a.flat(1/0)),a.min=(...a)=>c(...a.flat(1/0))))(Math)
// ( (M, {max, min} = M) => !M.sum && (	// /]/.test(max) && (
// 		M.sum = (...args) => args.flat(Infinity).reduce( (curr, v) => +v + curr, 0),
// 		M.avg = (...args) => Math.sum(args) / args.flat(Infinity).length,
// 		M.max = (...args) => max(...args.flat(Infinity)),
// 		M.min = (...args) => min(...args.flat(Infinity))
// 	)
// )(Math);



console.log(Math.sum);
// (...args) => flat(args).reduce( (curr, v) => +v + curr, 0)	// AKA (...args) => args.flat(Infinity).reduce( (curr, v) => +v + curr, 0)

console.log(Math.avg);
// (...args) => Math.sum(args) / flat(args).length	// AKA (...args) => Math.sum(args) / args.flat(Infinity).length

console.log(Math.max);
// (...args) => max(...flat(args))	// AKA (...args) => max(...args.flat(Infinity))

console.log(Math.min);
// (...args) => min(...flat(args))	// AKA (...args) => min(...args.flat(Infinity))

console.log(Math.min(5, "2", [3, "1", 4, 6]));
// 1 (no need for a "workaround" to process elements of an Array passed to the built-in Math.max and Math.min)

console.log(Math.min(5, "2", ...[3, "1", 4, 6]));
// 1  (BUT original functionality unchanged; code still works if it uses "workaround" to process elements of an Array)

console.log(Math.min(5, "2", 3, "1", 4, 6));
// 1  (again, original functionality unchanged)

console.log(Math.sum(5, "2", [3, "1", 4, 6]));
// 21

console.log(Math.sum(5, "2", ...[3, "1", 4, 6]));
// 21

console.log(Math.avg(5, "2", [3, "1", 4, 6]));
// 3.5

console.log(Math.avg(5, "2", ...[3, "1", 4, 6]));
// 3.5