665384534138 has 8 divisors (see below), whose sum is σ = 1056787201332. Its totient is φ = 313122133696.

The previous prime is 665384534137. The next prime is 665384534153. The reversal of 665384534138 is 831435483566.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 653547746929 + 11836787209 = 808423^2 + 108797^2 .

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

It is not an unprimeable number, because it can be changed into a prime (665384534131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9785066645 + ... + 9785066712.

Almost surely, 2^665384534138 is an apocalyptic number.

665384534138 is a deficient number, since it is larger than the sum of its proper divisors (391402667194).

665384534138 is a wasteful number, since it uses less digits than its factorization.

665384534138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19570133376.

The product of its digits is 24883200, while the sum is 56.

The spelling of 665384534138 in words is "six hundred sixty-five billion, three hundred eighty-four million, five hundred thirty-four thousand, one hundred thirty-eight".