21543443024 has 10 divisors (see below), whose sum is σ = 41740420890. Its totient is φ = 10771721504.

The previous prime is 21543442997. The next prime is 21543443041. The reversal of 21543443024 is 42034434512.

It can be written as a sum of positive squares in only one way, i.e., 13183632400 + 8359810624 = 114820^2 + 91432^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 673232579 + ... + 673232610.

It is an arithmetic number, because the mean of its divisors is an integer number (4174042089).

Almost surely, 2^21543443024 is an apocalyptic number.

It is an amenable number.

21543443024 is a deficient number, since it is larger than the sum of its proper divisors (20196977866).

21543443024 is a wasteful number, since it uses less digits than its factorization.

21543443024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346465197 (or 1346465191 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 32.

Adding to 21543443024 its reverse (42034434512), we get a palindrome (63577877536).

The spelling of 21543443024 in words is "twenty-one billion, five hundred forty-three million, four hundred forty-three thousand, twenty-four".