306665 has 4 divisors (see below), whose sum is σ = 368004. Its totient is φ = 245328.

The previous prime is 306661. The next prime is 306689. The reversal of 306665 is 566603.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566603 = 103 ⋅5501.

It can be written as a sum of positive squares in 2 ways, for example, as 226576 + 80089 = 476^2 + 283^2 .

It is a cyclic number.

It is not a de Polignac number, because 306665 - 2² = 306661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (306661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30662 + ... + 30671.

It is an arithmetic number, because the mean of its divisors is an integer number (92001).

2³⁰⁶⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

306665 is a deficient number, since it is larger than the sum of its proper divisors (61339).

306665 is an equidigital number, since it uses as much as digits as its factorization.

306665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61338.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 306665 is about 553.7734193693. The cubic root of 306665 is about 67.4354206306.

The spelling of 306665 in words is "three hundred six thousand, six hundred sixty-five".