numbers.js

function numbers(integers) {
    let integerList = integers.split(` `).map(Number);
    let averageValue = 0;
    let sum = 0;
    let topIntCounter = 0;
    let topIntFound = false;
    let result = [];

    for (let x of integerList) {
        sum += x;
    }
    averageValue = sum / integerList.length;

    while (Math.max.apply(Math, integerList) > averageValue) {
        topIntFound = true;
        let integerIndex = integerList.indexOf(Math.max.apply(Math, integerList));
        topIntCounter++;
        if (topIntCounter <= 5) {
            result.push(integerList[integerIndex]);
        }
        integerList.splice(integerIndex, 1);
    }
    topIntFound ? console.log(result.join(` `)) : console.log("No");
}

numbers('10 20 30 40 50');
numbers('5 2 3 4 -10 30 40 50 20 50 60 60 51');
numbers('1');
numbers('-1 -2 -3 -4 -5 -6');