328661 has 4 divisors (see below), whose sum is σ = 348012. Its totient is φ = 309312.

The previous prime is 328651. The next prime is 328667. The reversal of 328661 is 166823.

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 286225 + 42436 = 535^2 + 206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-328661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 328661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (328667) 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, 9650 + ... + 9683.

It is an arithmetic number, because the mean of its divisors is an integer number (87003).

2³²⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

328661 is a deficient number, since it is larger than the sum of its proper divisors (19351).

328661 is a wasteful number, since it uses less digits than its factorization.

328661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19350.

The product of its digits is 1728, while the sum is 26.

The square root of 328661 is about 573.2896301173. The cubic root of 328661 is about 69.0106403811.

It can be divided in two parts, 328 and 661, that added together give a palindrome (989).

The spelling of 328661 in words is "three hundred twenty-eight thousand, six hundred sixty-one".