678655 has 4 divisors (see below), whose sum is σ = 814392. Its totient is φ = 542920.

The previous prime is 678653. The next prime is 678659. The reversal of 678655 is 556876.

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

It is not a de Polignac number, because 678655 - 2¹ = 678653 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678653) 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, 67861 + ... + 67870.

It is an arithmetic number, because the mean of its divisors is an integer number (203598).

2⁶⁷⁸⁶⁵⁵ is an apocalyptic number.

678655 is a deficient number, since it is larger than the sum of its proper divisors (135737).

678655 is a wasteful number, since it uses less digits than its factorization.

678655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135736.

The product of its digits is 50400, while the sum is 37.

The square root of 678655 is about 823.8051954194. The cubic root of 678655 is about 87.8785773725.

The spelling of 678655 in words is "six hundred seventy-eight thousand, six hundred fifty-five".