21343443440 has 80 divisors (see below), whose sum is σ = 55156264416. Its totient is φ = 7614796800.

The previous prime is 21343443427. The next prime is 21343443521. The reversal of 21343443440 is 4434434312.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 21343443397 and 21343443406.

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 15 ways as a sum of consecutive naturals, for example, 182171 + ... + 275450.

Almost surely, 2^21343443440 is an apocalyptic number.

21343443440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21343443440 is an abundant number, since it is smaller than the sum of its proper divisors (33812820976).

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

21343443440 is a wasteful number, since it uses less digits than its factorization.

21343443440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457698 (or 457692 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 32.

Adding to 21343443440 its reverse (4434434312), we get a palindrome (25777877752).

The spelling of 21343443440 in words is "twenty-one billion, three hundred forty-three million, four hundred forty-three thousand, four hundred forty".