21312040444 has 12 divisors (see below), whose sum is σ = 37326229864. Its totient is φ = 10647403344.

The previous prime is 21312040411. The next prime is 21312040447. The reversal of 21312040444 is 44404021312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312040447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2148654 + ... + 2158549.

Almost surely, 2^21312040444 is an apocalyptic number.

It is an amenable number.

21312040444 is a deficient number, since it is larger than the sum of its proper divisors (16014189420).

21312040444 is a wasteful number, since it uses less digits than its factorization.

21312040444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4308444 (or 4308442 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21312040444 its reverse (44404021312), we get a palindrome (65716061756).

The spelling of 21312040444 in words is "twenty-one billion, three hundred twelve million, forty thousand, four hundred forty-four".