328521 has 4 divisors (see below), whose sum is σ = 438032. Its totient is φ = 219012.

The previous prime is 328519. The next prime is 328543. The reversal of 328521 is 125823.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125823 = 3 ⋅41941.

It is not a de Polignac number, because 328521 - 2¹ = 328519 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (328511) 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 in 3 ways as a sum of consecutive naturals, for example, 54751 + ... + 54756.

It is an arithmetic number, because the mean of its divisors is an integer number (109508).

328521 is a Friedman number, since it can be written as 12+(8^2+5)^3, using all its digits and the basic arithmetic operations.

2³²⁸⁵²¹ is an apocalyptic number.

It is an amenable number.

328521 is a deficient number, since it is larger than the sum of its proper divisors (109511).

328521 is a wasteful number, since it uses less digits than its factorization.

328521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109510.

The product of its digits is 480, while the sum is 21.

The square root of 328521 is about 573.1675147808. The cubic root of 328521 is about 69.0008401494. Note that the first 3 decimals are identical.

The spelling of 328521 in words is "three hundred twenty-eight thousand, five hundred twenty-one".