678949 has 2 divisors, whose sum is σ = 678950. Its totient is φ = 678948.

The previous prime is 678943. The next prime is 678959. The reversal of 678949 is 949876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 381924 + 297025 = 618^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 678949 - 2³ = 678941 is a 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 (678941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339474 + 339475.

It is an arithmetic number, because the mean of its divisors is an integer number (339475).

2⁶⁷⁸⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

678949 is a deficient number, since it is larger than the sum of its proper divisors (1).

678949 is an equidigital number, since it uses as much as digits as its factorization.

678949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 678949 is about 823.9836163420. The cubic root of 678949 is about 87.8912654943.

The spelling of 678949 in words is "six hundred seventy-eight thousand, nine hundred forty-nine".