678808321 has 4 divisors (see below), whose sum is σ = 685152432. Its totient is φ = 672464212.

The previous prime is 678808313. The next prime is 678808331. The reversal of 678808321 is 123808876.

It is a happy number.

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 678808321 - 2³ = 678808313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678808301) 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 in 3 ways as a sum of consecutive naturals, for example, 3171895 + ... + 3172108.

It is an arithmetic number, because the mean of its divisors is an integer number (171288108).

Almost surely, 2^678808321 is an apocalyptic number.

It is an amenable number.

678808321 is a deficient number, since it is larger than the sum of its proper divisors (6344111).

678808321 is a wasteful number, since it uses less digits than its factorization.

678808321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6344110.

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 678808321 is about 26053.9501995379. The cubic root of 678808321 is about 878.8519468511.

The spelling of 678808321 in words is "six hundred seventy-eight million, eight hundred eight thousand, three hundred twenty-one".