678636 has 36 divisors (see below), whose sum is σ = 1961232. Its totient is φ = 193824.

The previous prime is 678631. The next prime is 678637. The reversal of 678636 is 636876.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 678636.

It is not an unprimeable number, because it can be changed into a prime (678631) 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 11 ways as a sum of consecutive naturals, for example, 1095 + ... + 1598.

2⁶⁷⁸⁶³⁶ is an apocalyptic number.

It is an amenable number.

678636 is an abundant number, since it is smaller than the sum of its proper divisors (1282596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

678636 is a wasteful number, since it uses less digits than its factorization.

678636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2710 (or 2705 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 678636 is about 823.7936634862. The cubic root of 678636 is about 87.8777572658.

The spelling of 678636 in words is "six hundred seventy-eight thousand, six hundred thirty-six".