21440402044 has 6 divisors (see below), whose sum is σ = 37520703584. Its totient is φ = 10720201020.

The previous prime is 21440402041. The next prime is 21440402059. The reversal of 21440402044 is 44020404412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440402041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2680050252 + ... + 2680050259.

Almost surely, 2^21440402044 is an apocalyptic number.

It is an amenable number.

21440402044 is a deficient number, since it is larger than the sum of its proper divisors (16080301540).

21440402044 is a wasteful number, since it uses less digits than its factorization.

21440402044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5360100515 (or 5360100513 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 21440402044 its reverse (44020404412), we get a palindrome (65460806456).

The spelling of 21440402044 in words is "twenty-one billion, four hundred forty million, four hundred two thousand, forty-four".