678484391 has 4 divisors (see below), whose sum is σ = 730675512. Its totient is φ = 626293272.

The previous prime is 678484379. The next prime is 678484393. The reversal of 678484391 is 193484876.

678484391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678484391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678484393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26095541 + ... + 26095566.

It is an arithmetic number, because the mean of its divisors is an integer number (182668878).

Almost surely, 2^678484391 is an apocalyptic number.

678484391 is a deficient number, since it is larger than the sum of its proper divisors (52191121).

678484391 is a wasteful number, since it uses less digits than its factorization.

678484391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52191120.

The product of its digits is 1161216, while the sum is 50.

The square root of 678484391 is about 26047.7329339810. The cubic root of 678484391 is about 878.7121274063.

The spelling of 678484391 in words is "six hundred seventy-eight million, four hundred eighty-four thousand, three hundred ninety-one".