678851 has 4 divisors (see below), whose sum is σ = 714600. Its totient is φ = 643104.

The previous prime is 678833. The next prime is 678859. The reversal of 678851 is 158876.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 678851 - 2¹⁰ = 677827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678859) 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, 17846 + ... + 17883.

It is an arithmetic number, because the mean of its divisors is an integer number (178650).

2⁶⁷⁸⁸⁵¹ is an apocalyptic number.

678851 is a deficient number, since it is larger than the sum of its proper divisors (35749).

678851 is a wasteful number, since it uses less digits than its factorization.

678851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35748.

The product of its digits is 13440, while the sum is 35.

The square root of 678851 is about 823.9241469941. The cubic root of 678851 is about 87.8870365274.

The spelling of 678851 in words is "six hundred seventy-eight thousand, eight hundred fifty-one".