678647 has 2 divisors, whose sum is σ = 678648. Its totient is φ = 678646.

The previous prime is 678641. The next prime is 678649. The reversal of 678647 is 746876.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 678647 - 2⁴ = 678631 is a prime.

Together with 678649, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 678647.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 678647.

It is not a weakly prime, because it can be changed into another prime (678641) 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 as a sum of consecutive naturals, namely, 339323 + 339324.

It is an arithmetic number, because the mean of its divisors is an integer number (339324).

2⁶⁷⁸⁶⁴⁷ is an apocalyptic number.

678647 is a deficient number, since it is larger than the sum of its proper divisors (1).

678647 is an equidigital number, since it uses as much as digits as its factorization.

678647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 38.

The square root of 678647 is about 823.8003398883. The cubic root of 678647 is about 87.8782320663.

The spelling of 678647 in words is "six hundred seventy-eight thousand, six hundred forty-seven".