678239 has 4 divisors (see below), whose sum is σ = 694056. Its totient is φ = 662424.

The previous prime is 678229. The next prime is 678253. The reversal of 678239 is 932876.

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 678239 - 2⁸ = 677983 is a prime.

It is a super-2 number, since 2×678239² = 920016282242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 678199 and 678208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678229) 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, 7844 + ... + 7929.

It is an arithmetic number, because the mean of its divisors is an integer number (173514).

2⁶⁷⁸²³⁹ is an apocalyptic number.

678239 is a deficient number, since it is larger than the sum of its proper divisors (15817).

678239 is a wasteful number, since it uses less digits than its factorization.

678239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15816.

The product of its digits is 18144, while the sum is 35.

The square root of 678239 is about 823.5526698396. The cubic root of 678239 is about 87.8606178495.

The spelling of 678239 in words is "six hundred seventy-eight thousand, two hundred thirty-nine".