66888609 has 4 divisors (see below), whose sum is σ = 89184816. Its totient is φ = 44592404.

The previous prime is 66888599. The next prime is 66888617. The reversal of 66888609 is 90688866.

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 not a de Polignac number, because 66888609 - 2⁴ = 66888593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66888629) 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, 11148099 + ... + 11148104.

It is an arithmetic number, because the mean of its divisors is an integer number (22296204).

Almost surely, 2^66888609 is an apocalyptic number.

It is an amenable number.

66888609 is a deficient number, since it is larger than the sum of its proper divisors (22296207).

66888609 is a wasteful number, since it uses less digits than its factorization.

66888609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22296206.

The product of its (nonzero) digits is 995328, while the sum is 51.

The square root of 66888609 is about 8178.5456531097. The cubic root of 66888609 is about 405.9296006614.

The spelling of 66888609 in words is "sixty-six million, eight hundred eighty-eight thousand, six hundred nine".