21440422424 has 8 divisors (see below), whose sum is σ = 40200792060. Its totient is φ = 10720211208.

The previous prime is 21440422387. The next prime is 21440422429. The reversal of 21440422424 is 42422404412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440422429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340026394 + ... + 1340026409.

Almost surely, 2^21440422424 is an apocalyptic number.

It is an amenable number.

21440422424 is a deficient number, since it is larger than the sum of its proper divisors (18760369636).

21440422424 is a wasteful number, since it uses less digits than its factorization.

21440422424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680052809 (or 2680052805 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 29.

Adding to 21440422424 its reverse (42422404412), we get a palindrome (63862826836).

The spelling of 21440422424 in words is "twenty-one billion, four hundred forty million, four hundred twenty-two thousand, four hundred twenty-four".