6646624321 has 2 divisors, whose sum is σ = 6646624322. Its totient is φ = 6646624320.

The previous prime is 6646624253. The next prime is 6646624343. The reversal of 6646624321 is 1234266466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6276600625 + 370023696 = 79225^2 + 19236^2 .

It is a cyclic number.

It is not a de Polignac number, because 6646624321 - 2¹³ = 6646616129 is a prime.

It is a super-2 number, since 2×6646624321² = 88355229729017422082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6646621321) 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 as a sum of consecutive naturals, namely, 3323312160 + 3323312161.

It is an arithmetic number, because the mean of its divisors is an integer number (3323312161).

Almost surely, 2^6646624321 is an apocalyptic number.

It is an amenable number.

6646624321 is a deficient number, since it is larger than the sum of its proper divisors (1).

6646624321 is an equidigital number, since it uses as much as digits as its factorization.

6646624321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 40.

The square root of 6646624321 is about 81526.8319082742. The cubic root of 6646624321 is about 1880.1841076111.

The spelling of 6646624321 in words is "six billion, six hundred forty-six million, six hundred twenty-four thousand, three hundred twenty-one".