• 678 can be written using four 4's:

678 has 8 divisors (see below), whose sum is σ = 1368. Its totient is φ = 224.

The previous prime is 677. The next prime is 683. The reversal of 678 is 876.

678 is nontrivially palindromic in base 15.

678 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

678 is an esthetic number in base 10 and base 11, because in such bases its adjacent digits differ by 1.

It is a sphenic number, since it is the product of 3 distinct primes.

678 is an admirable number.

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

678 is an undulating number in base 15.

It is a straight-line number, since its digits are in arithmetic progression.

It is a plaindrome in base 8, base 10, base 11 and base 14.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51 + ... + 62.

It is an arithmetic number, because the mean of its divisors is an integer number (171).

678 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (684).

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

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

The sum of its prime factors is 118.

The product of its digits is 336, while the sum is 21.

The square root of 678 is about 26.0384331326. The cubic root of 678 is about 8.7850296436.

The spelling of 678 in words is "six hundred seventy-eight", and thus it is an aban number and an oban number.

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