678989 has 2 divisors, whose sum is σ = 678990. Its totient is φ = 678988.

The previous prime is 678971. The next prime is 679033. The reversal of 678989 is 989876.

678989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

678989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 469225 + 209764 = 685^2 + 458^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678989 is a prime.

It is a super-2 number, since 2×678989² = 922052124242, which contains 22 as substring.

It is a Chen prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339494 + 339495.

It is an arithmetic number, because the mean of its divisors is an integer number (339495).

2⁶⁷⁸⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

678989 is a deficient number, since it is larger than the sum of its proper divisors (1).

678989 is an equidigital number, since it uses as much as digits as its factorization.

678989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The square root of 678989 is about 824.0078883118. The cubic root of 678989 is about 87.8929914862.

The spelling of 678989 in words is "six hundred seventy-eight thousand, nine hundred eighty-nine".