665180081365 has 16 divisors (see below), whose sum is σ = 825849788400. Its totient is φ = 513726449152.

The previous prime is 665180081333. The next prime is 665180081381. The reversal of 665180081365 is 563180081566.

It can be written as a sum of positive squares in 8 ways, for example, as 79904590276 + 585275491089 = 282674^2 + 765033^2 .

It is a cyclic number.

It is not a de Polignac number, because 665180081365 - 2⁵ = 665180081333 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 813651 + ... + 1411519.

It is an arithmetic number, because the mean of its divisors is an integer number (51615611775).

Almost surely, 2^665180081365 is an apocalyptic number.

It is an amenable number.

665180081365 is a deficient number, since it is larger than the sum of its proper divisors (160669707035).

665180081365 is a wasteful number, since it uses less digits than its factorization.

665180081365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605576.

The product of its (nonzero) digits is 1036800, while the sum is 49.

The spelling of 665180081365 in words is "six hundred sixty-five billion, one hundred eighty million, eighty-one thousand, three hundred sixty-five".