678686 has 8 divisors (see below), whose sum is σ = 1034904. Its totient is φ = 333720.

The previous prime is 678659. The next prime is 678719. The reversal of 678686 is 686876.

678686 = 74² + 75² + ... + 134².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×678686² = 921229373192, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 2660 + ... + 2903.

It is an arithmetic number, because the mean of its divisors is an integer number (129363).

2⁶⁷⁸⁶⁸⁶ is an apocalyptic number.

678686 is a deficient number, since it is larger than the sum of its proper divisors (356218).

678686 is a wasteful number, since it uses less digits than its factorization.

678686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5626.

The product of its digits is 96768, while the sum is 41.

The square root of 678686 is about 823.8240103323. The cubic root of 678686 is about 87.8799154085.

The spelling of 678686 in words is "six hundred seventy-eight thousand, six hundred eighty-six".