21344003440 has 40 divisors (see below), whose sum is σ = 51225614208. Its totient is φ = 8262193920.

The previous prime is 21344003437. The next prime is 21344003453. The reversal of 21344003440 is 4430044312.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4300747 + ... + 4305706.

Almost surely, 2^21344003440 is an apocalyptic number.

21344003440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21344003440 is an abundant number, since it is smaller than the sum of its proper divisors (29881610768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21344003440 is a wasteful number, since it uses less digits than its factorization.

21344003440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8606497 (or 8606491 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21344003440 its reverse (4430044312), we get a palindrome (25774047752).

The spelling of 21344003440 in words is "twenty-one billion, three hundred forty-four million, three thousand, four hundred forty".