678391 has 8 divisors (see below), whose sum is σ = 780800. Its totient is φ = 577368.

The previous prime is 678383. The next prime is 678401. The reversal of 678391 is 193876.

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 678391 - 2³ = 678383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678341) 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, 1150 + ... + 1636.

It is an arithmetic number, because the mean of its divisors is an integer number (97600).

2⁶⁷⁸³⁹¹ is an apocalyptic number.

678391 is a deficient number, since it is larger than the sum of its proper divisors (102409).

678391 is a wasteful number, since it uses less digits than its factorization.

678391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693.

The product of its digits is 9072, while the sum is 34.

The square root of 678391 is about 823.6449477779. The cubic root of 678391 is about 87.8671808341.

The spelling of 678391 in words is "six hundred seventy-eight thousand, three hundred ninety-one".