678399 has 4 divisors (see below), whose sum is σ = 904536. Its totient is φ = 452264.

The previous prime is 678383. The next prime is 678401. The reversal of 678399 is 993876.

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 678399 - 2⁴ = 678383 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 678399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678329) 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, 113064 + ... + 113069.

It is an arithmetic number, because the mean of its divisors is an integer number (226134).

2⁶⁷⁸³⁹⁹ is an apocalyptic number.

678399 is a deficient number, since it is larger than the sum of its proper divisors (226137).

678399 is a wasteful number, since it uses less digits than its factorization.

678399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226136.

The product of its digits is 81648, while the sum is 42.

The square root of 678399 is about 823.6498042251. The cubic root of 678399 is about 87.8675262272.

The spelling of 678399 in words is "six hundred seventy-eight thousand, three hundred ninety-nine".