6666044561 has 4 divisors (see below), whose sum is σ = 7272048624. Its totient is φ = 6060040500.

The previous prime is 6666044533. The next prime is 6666044617. The reversal of 6666044561 is 1654406666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6666044561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6666044261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303002015 + ... + 303002036.

It is an arithmetic number, because the mean of its divisors is an integer number (1818012156).

Almost surely, 2^6666044561 is an apocalyptic number.

It is an amenable number.

6666044561 is a deficient number, since it is larger than the sum of its proper divisors (606004063).

6666044561 is a wasteful number, since it uses less digits than its factorization.

6666044561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606004062.

The product of its (nonzero) digits is 622080, while the sum is 44.

The square root of 6666044561 is about 81645.8484002708. The cubic root of 6666044561 is about 1882.0135135564.

The spelling of 6666044561 in words is "six billion, six hundred sixty-six million, forty-four thousand, five hundred sixty-one".