6561624321 has 32 divisors (see below), whose sum is σ = 11114188800. Its totient is φ = 3747960720.

The previous prime is 6561624313. The next prime is 6561624343. The reversal of 6561624321 is 1234261656.

6561624321 is a `hidden beast` number, since 6 + 5 + 6 + 1 + 624 + 3 + 21 = 666.

6561624321 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6561624321 - 2³ = 6561624313 is a prime.

It is a super-2 number, since 2×6561624321² = 86109827459877422082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6561624721) by changing a digit.

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 in 31 ways as a sum of consecutive naturals, for example, 583926 + ... + 595056.

It is an arithmetic number, because the mean of its divisors is an integer number (347318400).

Almost surely, 2^6561624321 is an apocalyptic number.

It is an amenable number.

6561624321 is a deficient number, since it is larger than the sum of its proper divisors (4552564479).

6561624321 is a wasteful number, since it uses less digits than its factorization.

6561624321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14266 (or 14260 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 6561624321 is about 81003.8537416585. The cubic root of 6561624321 is about 1872.1348188365.

Adding to 6561624321 its reverse (1234261656), we get a palindrome (7795885977).

The spelling of 6561624321 in words is "six billion, five hundred sixty-one million, six hundred twenty-four thousand, three hundred twenty-one".