666309 has 8 divisors (see below), whose sum is σ = 1015360. Its totient is φ = 380736.

The previous prime is 666301. The next prime is 666329. The reversal of 666309 is 903666.

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

It is not a de Polignac number, because 666309 - 2³ = 666301 is a prime.

It is a Duffinian number.

666309 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666301) 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, 15844 + ... + 15885.

It is an arithmetic number, because the mean of its divisors is an integer number (126920).

2⁶⁶⁶³⁰⁹ is an apocalyptic number.

It is an amenable number.

666309 is a deficient number, since it is larger than the sum of its proper divisors (349051).

666309 is a wasteful number, since it uses less digits than its factorization.

666309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31739.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 666309 is about 816.2775263353. The cubic root of 666309 is about 87.3424211483.

The spelling of 666309 in words is "six hundred sixty-six thousand, three hundred nine".