328781 has 2 divisors, whose sum is σ = 328782. Its totient is φ = 328780.

The previous prime is 328777. The next prime is 328787. The reversal of 328781 is 187823.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 292681 + 36100 = 541^2 + 190^2 .

It is an emirp because it is prime and its reverse (187823) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 328781 - 2² = 328777 is a prime.

It is a super-2 number, since 2×328781² = 216193891922, which contains 22 as substring.

It is an Ulam number.

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 328781.

It is not a weakly prime, because it can be changed into another prime (328787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 164390 + 164391.

It is an arithmetic number, because the mean of its divisors is an integer number (164391).

2³²⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

328781 is a deficient number, since it is larger than the sum of its proper divisors (1).

328781 is an equidigital number, since it uses as much as digits as its factorization.

328781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 29.

The square root of 328781 is about 573.3942797064. The cubic root of 328781 is about 69.0190383648.

The spelling of 328781 in words is "three hundred twenty-eight thousand, seven hundred eighty-one".