665995 has 8 divisors (see below), whose sum is σ = 871920. Its totient is φ = 484320.

The previous prime is 665993. The next prime is 666013. The reversal of 665995 is 599566.

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

It is not a de Polignac number, because 665995 - 2¹ = 665993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6000 + ... + 6109.

It is an arithmetic number, because the mean of its divisors is an integer number (108990).

2⁶⁶⁵⁹⁹⁵ is an apocalyptic number.

665995 is a deficient number, since it is larger than the sum of its proper divisors (205925).

665995 is a wasteful number, since it uses less digits than its factorization.

665995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12125.

The product of its digits is 72900, while the sum is 40.

The square root of 665995 is about 816.0851671241. The cubic root of 665995 is about 87.3286988716.

The spelling of 665995 in words is "six hundred sixty-five thousand, nine hundred ninety-five".