678643 has 8 divisors (see below), whose sum is σ = 787712. Its totient is φ = 572616.

The previous prime is 678641. The next prime is 678647. The reversal of 678643 is 346876.

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

It is a cyclic number.

It is not a de Polignac number, because 678643 - 2¹ = 678641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 678599 and 678608.

It is not an unprimeable number, because it can be changed into a prime (678641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255 + ... + 1192.

It is an arithmetic number, because the mean of its divisors is an integer number (98464).

2⁶⁷⁸⁶⁴³ is an apocalyptic number.

678643 is a deficient number, since it is larger than the sum of its proper divisors (109069).

678643 is a wasteful number, since it uses less digits than its factorization.

678643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1521.

The product of its digits is 24192, while the sum is 34.

The square root of 678643 is about 823.7979121119. The cubic root of 678643 is about 87.8780594122.

The spelling of 678643 in words is "six hundred seventy-eight thousand, six hundred forty-three".