665596538 has 8 divisors (see below), whose sum is σ = 999023220. Its totient is φ = 332588800.

The previous prime is 665596537. The next prime is 665596541. The reversal of 665596538 is 835695566.

It can be written as a sum of positive squares in 2 ways, for example, as 528402169 + 137194369 = 22987^2 + 11713^2 .

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 665596538.

It is not an unprimeable number, because it can be changed into a prime (665596531) 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, 100733 + ... + 107136.

Almost surely, 2^665596538 is an apocalyptic number.

665596538 is a deficient number, since it is larger than the sum of its proper divisors (333426682).

665596538 is a wasteful number, since it uses less digits than its factorization.

665596538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209472.

The product of its digits is 5832000, while the sum is 53.

The square root of 665596538 is about 25799.1576994289. The cubic root of 665596538 is about 873.1127926633.

The spelling of 665596538 in words is "six hundred sixty-five million, five hundred ninety-six thousand, five hundred thirty-eight".