678861 has 30 divisors (see below), whose sum is σ = 1114410. Its totient is φ = 411264.

The previous prime is 678859. The next prime is 678871. The reversal of 678861 is 168876.

It can be written as a sum of positive squares in 3 ways, for example, as 281961 + 396900 = 531^2 + 630^2 .

It is not a de Polignac number, because 678861 - 2¹ = 678859 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 678861.

It is not an unprimeable number, because it can be changed into a prime (678871) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 23395 + ... + 23423.

It is an arithmetic number, because the mean of its divisors is an integer number (37147).

2⁶⁷⁸⁸⁶¹ is an apocalyptic number.

It is an amenable number.

678861 is a deficient number, since it is larger than the sum of its proper divisors (435549).

678861 is a wasteful number, since it uses less digits than its factorization.

678861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 49 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 678861 is about 823.9302154916. The cubic root of 678861 is about 87.8874680733.

The spelling of 678861 in words is "six hundred seventy-eight thousand, eight hundred sixty-one".