6628804561 has 4 divisors (see below), whose sum is σ = 6630718900. Its totient is φ = 6626890224.

The previous prime is 6628804537. The next prime is 6628804579. The reversal of 6628804561 is 1654088266.

6628804561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1045875600 + 5582928961 = 32340^2 + 74719^2 .

It is a cyclic number.

It is not a de Polignac number, because 6628804561 - 2¹⁷ = 6628673489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6628804591) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 951966 + ... + 958903.

It is an arithmetic number, because the mean of its divisors is an integer number (1657679725).

Almost surely, 2^6628804561 is an apocalyptic number.

It is an amenable number.

6628804561 is a deficient number, since it is larger than the sum of its proper divisors (1914339).

6628804561 is a wasteful number, since it uses less digits than its factorization.

6628804561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1914338.

The product of its (nonzero) digits is 552960, while the sum is 46.

The square root of 6628804561 is about 81417.4708585326. The cubic root of 6628804561 is about 1878.5023307837.

The spelling of 6628804561 in words is "six billion, six hundred twenty-eight million, eight hundred four thousand, five hundred sixty-one".