665355585128 has 16 divisors (see below), whose sum is σ = 1343506470180. Its totient is φ = 307087193088.

The previous prime is 665355585107. The next prime is 665355585173. The reversal of 665355585128 is 821585553566.

It can be written as a sum of positive squares in 2 ways, for example, as 610682857444 + 54672727684 = 781462^2 + 233822^2 .

It is a super-2 number, since 2×665355585128² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3198824825 + ... + 3198825032.

Almost surely, 2^665355585128 is an apocalyptic number.

It is an amenable number.

665355585128 is an abundant number, since it is smaller than the sum of its proper divisors (678150885052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665355585128 is a wasteful number, since it uses less digits than its factorization.

665355585128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6397649876 (or 6397649872 counting only the distinct ones).

The product of its digits is 43200000, while the sum is 59.

The spelling of 665355585128 in words is "six hundred sixty-five billion, three hundred fifty-five million, five hundred eighty-five thousand, one hundred twenty-eight".