678305 has 4 divisors (see below), whose sum is σ = 813972. Its totient is φ = 542640.

The previous prime is 678299. The next prime is 678329. The reversal of 678305 is 503876.

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 165649 + 512656 = 407^2 + 716^2 .

It is not a de Polignac number, because 678305 - 2⁴ = 678289 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67826 + ... + 67835.

It is an arithmetic number, because the mean of its divisors is an integer number (203493).

2⁶⁷⁸³⁰⁵ is an apocalyptic number.

It is an amenable number.

678305 is a deficient number, since it is larger than the sum of its proper divisors (135667).

678305 is a wasteful number, since it uses less digits than its factorization.

678305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135666.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 678305 is about 823.5927391618. The cubic root of 678305 is about 87.8634676869.

The spelling of 678305 in words is "six hundred seventy-eight thousand, three hundred five".