306689 has 2 divisors, whose sum is σ = 306690. Its totient is φ = 306688.

The previous prime is 306661. The next prime is 306701. The reversal of 306689 is 986603.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160000 + 146689 = 400^2 + 383^2 .

It is a cyclic number.

It is not a de Polignac number, because 306689 - 2¹² = 302593 is a prime.

It is not a weakly prime, because it can be changed into another prime (306389) 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 as a sum of consecutive naturals, namely, 153344 + 153345.

It is an arithmetic number, because the mean of its divisors is an integer number (153345).

2³⁰⁶⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

306689 is a deficient number, since it is larger than the sum of its proper divisors (1).

306689 is an equidigital number, since it uses as much as digits as its factorization.

306689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 306689 is about 553.7950884578. The cubic root of 306689 is about 67.4371797791.

The spelling of 306689 in words is "three hundred six thousand, six hundred eighty-nine".