678638 has 8 divisors (see below), whose sum is σ = 1062288. Its totient is φ = 324544.

The previous prime is 678637. The next prime is 678641. The reversal of 678638 is 836876.

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

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678631) 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, 7331 + ... + 7422.

It is an arithmetic number, because the mean of its divisors is an integer number (132786).

2⁶⁷⁸⁶³⁸ is an apocalyptic number.

678638 is a deficient number, since it is larger than the sum of its proper divisors (383650).

678638 is a wasteful number, since it uses less digits than its factorization.

678638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14778.

The product of its digits is 48384, while the sum is 38.

The square root of 678638 is about 823.7948773815. The cubic root of 678638 is about 87.8778435935.

The spelling of 678638 in words is "six hundred seventy-eight thousand, six hundred thirty-eight".