678689 has 12 divisors (see below), whose sum is σ = 766080. Its totient is φ = 600600.

The previous prime is 678659. The next prime is 678719. The reversal of 678689 is 986876.

It is an interprime number because it is at equal distance from previous prime (678659) and next prime (678719).

It is not a de Polignac number, because 678689 - 2¹⁶ = 613153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8552 + ... + 8630.

It is an arithmetic number, because the mean of its divisors is an integer number (63840).

2⁶⁷⁸⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

678689 is a deficient number, since it is larger than the sum of its proper divisors (87391).

678689 is a wasteful number, since it uses less digits than its factorization.

678689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 161 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 678689 is about 823.8258311075. The cubic root of 678689 is about 87.8800448937.

The spelling of 678689 in words is "six hundred seventy-eight thousand, six hundred eighty-nine".