665896999 has 4 divisors (see below), whose sum is σ = 666143560. Its totient is φ = 665650440.

The previous prime is 665896993. The next prime is 665897017. The reversal of 665896999 is 999698566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665896999 - 2⁷ = 665896871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665896993) 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, 119184 + ... + 124645.

It is an arithmetic number, because the mean of its divisors is an integer number (166535890).

Almost surely, 2^665896999 is an apocalyptic number.

665896999 is a deficient number, since it is larger than the sum of its proper divisors (246561).

665896999 is a wasteful number, since it uses less digits than its factorization.

665896999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246560.

The product of its digits is 56687040, while the sum is 67.

The square root of 665896999 is about 25804.9801201241. The cubic root of 665896999 is about 873.2441519596.

The spelling of 665896999 in words is "six hundred sixty-five million, eight hundred ninety-six thousand, nine hundred ninety-nine".