I am new to ReactJs, my understanding of custom hooks is that they are used for separating logic into a function. In many of the custom hook examples I have seen uses some built-in hook (mostly useState and useEffect). Is it mandatory to use built-in hooks ?

If for example, I have a code like this (Fiddle)

export default function App() {
  const [data, setData] = useState();

  const isEven = checkEven(data);
  const isAboveHundred = checkIsAboveHundred(data);
  const isPrime = checkEven(data);

  return (
    <>
      <label>
        Enter number:
        <input
          type="number"
          value={data}
          onChange={(e) => setData(e.target.value)}
        />
      </label>

      <div> Number is {isEven ? 'even' : 'odd'}</div>
      <div> Number is {isAboveHundred ? 'above' : 'less'} than 100</div>
      <div> Number is {isPrime ? 'prime' : 'not prime'}</div>
    </>
  );
}

// helper functions
function checkEven(num) {
  const isEven = num % 2 === 0;

  return isEven;
}

function checkIsAboveHundred(num) {
  const isAboveHundred = num > 100;

  return isAboveHundred;
}

function checkPrime(num) {
  for (let i = 2, s = Math.sqrt(num); i <= s; i++) {
    if (num % i === 0) return false;
  }

  return num > 1;
}

and if I am asked to change these helper functions to custom hooks, is it fine to just rename them to useCheckEven, useCheckIsAboveHundred, useCheckPrime and keep the function body as it is.

Like this

// custom hooks
function useCheckEven(num) {
  const isEven = num % 2 === 0;

  return isEven;
}

function useCheckIsAboveHundred(num) {
  const isAboveHundred = num > 100;

  return isAboveHundred;
}

function useCheckPrime (num) {
  for (let i = 2, s = Math.sqrt(num); i <= s; i++) {
    if (num % i === 0) return false;
  }

  return num > 1;
}

Is it mandatory to wrap them in a useEffect (or useState) like below ? (Fiddle)

// custom hooks
function useCheckEven(num) {
  const [isEven, setIsEven] = useState(false);

  useEffect(() => {
    const newValue = num % 2 === 0;
    setIsEven(newValue);
  }, [num]);

  return isEven;
}

function useCheckIsAboveHundred(num) {
  const [isAboveHundred, setIsAboveHundred] = useState(false);

  useEffect(() => {
    const newValue = num > 100;
    setIsAboveHundred(newValue);
  }, [num]);

  return isAboveHundred;
}

function useCheckPrime(num) {
  const [isPrime, setIsPrime] = useState(false);

  // helper function
  // taken from /a/40200212/26420821
  // not sure if this should be in useCallback
  function checkPrime(num) {
    var sqrtnum = Math.floor(Math.sqrt(num));
    var prime = num != 1;
    for (var i = 2; i < sqrtnum + 1; i++) {
      // sqrtnum+1
      if (num % i == 0) {
        prime = false;
        break;
      }
    }
    return prime;
  }

  useEffect(() => {
    const newValue = checkPrime(num);
    setIsPrime(newValue);
  }, [num]);

  return isPrime;
}

I tried both ways and they seem to be working. I am not sure which way is right. Please guide