678109 has 4 divisors (see below), whose sum is σ = 707616. Its totient is φ = 648604.

The previous prime is 678103. The next prime is 678133. The reversal of 678109 is 901876.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 678109 - 2³ = 678101 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14719 + ... + 14764.

It is an arithmetic number, because the mean of its divisors is an integer number (176904).

2⁶⁷⁸¹⁰⁹ is an apocalyptic number.

It is an amenable number.

678109 is a deficient number, since it is larger than the sum of its proper divisors (29507).

678109 is a wasteful number, since it uses less digits than its factorization.

678109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29506.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 678109 is about 823.4737397149. The cubic root of 678109 is about 87.8550039925.

It can be divided in two parts, 678 and 109, that added together give a palindrome (787).

The spelling of 678109 in words is "six hundred seventy-eight thousand, one hundred nine".