660005 has 4 divisors (see below), whose sum is σ = 792012. Its totient is φ = 528000.

The previous prime is 660001. The next prime is 660013. The reversal of 660005 is 500066.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 450241 + 209764 = 671^2 + 458^2 .

It is not a de Polignac number, because 660005 - 2² = 660001 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 (660001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65996 + ... + 66005.

It is an arithmetic number, because the mean of its divisors is an integer number (198003).

2⁶⁶⁰⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

660005 is a deficient number, since it is larger than the sum of its proper divisors (132007).

660005 is a wasteful number, since it uses less digits than its factorization.

660005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132006.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 660005 is about 812.4069177450. The cubic root of 660005 is about 87.0660967745.

The spelling of 660005 in words is "six hundred sixty thousand, five".