666823707609 has 32 divisors (see below), whose sum is σ = 991144673280. Its totient is φ = 396298490112.

The previous prime is 666823707607. The next prime is 666823707619. The reversal of 666823707609 is 906707328666.

666823707609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666823707609 - 2¹ = 666823707607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666823707607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4940232 + ... + 5073414.

It is an arithmetic number, because the mean of its divisors is an integer number (30973271040).

Almost surely, 2^666823707609 is an apocalyptic number.

It is an amenable number.

666823707609 is a deficient number, since it is larger than the sum of its proper divisors (324320965671).

666823707609 is a wasteful number, since it uses less digits than its factorization.

666823707609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138389.

The product of its (nonzero) digits is 27433728, while the sum is 60.

The spelling of 666823707609 in words is "six hundred sixty-six billion, eight hundred twenty-three million, seven hundred seven thousand, six hundred nine".