665684616407 has 16 divisors (see below), whose sum is σ = 699115898880. Its totient is φ = 632638624992.

The previous prime is 665684616349. The next prime is 665684616427. The reversal of 665684616407 is 704616486566.

It is a cyclic number.

It is not a de Polignac number, because 665684616407 - 2¹⁰ = 665684615383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665684616427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2483168 + ... + 2738154.

It is an arithmetic number, because the mean of its divisors is an integer number (43694743680).

Almost surely, 2^665684616407 is an apocalyptic number.

665684616407 is a deficient number, since it is larger than the sum of its proper divisors (33431282473).

665684616407 is a wasteful number, since it uses less digits than its factorization.

665684616407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255742.

The product of its (nonzero) digits is 34836480, while the sum is 59.

The spelling of 665684616407 in words is "six hundred sixty-five billion, six hundred eighty-four million, six hundred sixteen thousand, four hundred seven".