678891 has 8 divisors (see below), whose sum is σ = 944640. Its totient is φ = 432872.

The previous prime is 678883. The next prime is 678901. The reversal of 678891 is 198876.

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

It is a cyclic number.

It is not a de Polignac number, because 678891 - 2³ = 678883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (678871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4851 + ... + 4988.

It is an arithmetic number, because the mean of its divisors is an integer number (118080).

2⁶⁷⁸⁸⁹¹ is an apocalyptic number.

678891 is a deficient number, since it is larger than the sum of its proper divisors (265749).

678891 is a wasteful number, since it uses less digits than its factorization.

678891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9865.

The product of its digits is 24192, while the sum is 39.

The square root of 678891 is about 823.9484207158. The cubic root of 678891 is about 87.8887626855. Note that the first 3 decimals are identical.

The spelling of 678891 in words is "six hundred seventy-eight thousand, eight hundred ninety-one".