678961 has 4 divisors (see below), whose sum is σ = 685300. Its totient is φ = 672624.

The previous prime is 678959. The next prime is 678971. The reversal of 678961 is 169876.

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

It can be written as a sum of positive squares in 2 ways, for example, as 409600 + 269361 = 640^2 + 519^2 .

It is a cyclic number.

It is not a de Polignac number, because 678961 - 2¹ = 678959 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 678961.

It is not an unprimeable number, because it can be changed into a prime (678901) 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, 3006 + ... + 3223.

It is an arithmetic number, because the mean of its divisors is an integer number (171325).

2⁶⁷⁸⁹⁶¹ is an apocalyptic number.

678961 is the 369-th centered decagonal number.

It is an amenable number.

678961 is a deficient number, since it is larger than the sum of its proper divisors (6339).

678961 is a wasteful number, since it uses less digits than its factorization.

678961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6338.

The product of its digits is 18144, while the sum is 37.

The square root of 678961 is about 823.9908980080. The cubic root of 678961 is about 87.8917832990.

The spelling of 678961 in words is "six hundred seventy-eight thousand, nine hundred sixty-one".