665830 has 16 divisors (see below), whose sum is σ = 1307664. Its totient is φ = 242080.

The previous prime is 665813. The next prime is 665843. The reversal of 665830 is 38566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2917 + ... + 3136.

It is an arithmetic number, because the mean of its divisors is an integer number (81729).

2⁶⁶⁵⁸³⁰ is an apocalyptic number.

665830 is a deficient number, since it is larger than the sum of its proper divisors (641834).

665830 is a wasteful number, since it uses less digits than its factorization.

665830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6071.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 665830 is about 815.9840684719. The cubic root of 665830 is about 87.3214863923.

Subtracting from 665830 its reverse (38566), we obtain a square (627264 = 792²).

The spelling of 665830 in words is "six hundred sixty-five thousand, eight hundred thirty".