665566615613 has 8 divisors (see below), whose sum is σ = 704750287032. Its totient is φ = 626386576896.

The previous prime is 665566615603. The next prime is 665566615793. The reversal of 665566615613 is 316516665566.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 374179336804 + 291387278809 = 611702^2 + 539803^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665566615613 - 2¹⁰ = 665566614589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665566615603) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 526370 + ... + 1268147.

It is an arithmetic number, because the mean of its divisors is an integer number (88093785879).

Almost surely, 2^665566615613 is an apocalyptic number.

It is an amenable number.

665566615613 is a deficient number, since it is larger than the sum of its proper divisors (39183671419).

665566615613 is a wasteful number, since it uses less digits than its factorization.

665566615613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1816351.

The product of its digits is 17496000, while the sum is 56.

The spelling of 665566615613 in words is "six hundred sixty-five billion, five hundred sixty-six million, six hundred fifteen thousand, six hundred thirteen".