328531 has 4 divisors (see below), whose sum is σ = 375472. Its totient is φ = 281592.

The previous prime is 328519. The next prime is 328543. The reversal of 328531 is 135823.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135823 = 71 ⋅1913.

It is an interprime number because it is at equal distance from previous prime (328519) and next prime (328543).

It is a cyclic number.

It is not a de Polignac number, because 328531 - 2¹³ = 320339 is a prime.

It is a super-2 number, since 2×328531² = 215865235922, which contains 22 as substring.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23460 + ... + 23473.

It is an arithmetic number, because the mean of its divisors is an integer number (93868).

2³²⁸⁵³¹ is an apocalyptic number.

328531 is a deficient number, since it is larger than the sum of its proper divisors (46941).

328531 is an equidigital number, since it uses as much as digits as its factorization.

328531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46940.

The product of its digits is 720, while the sum is 22.

The square root of 328531 is about 573.1762381676. The cubic root of 328531 is about 69.0015402583.

Subtracting from 328531 its sum of digits (22), we obtain a cube (328509 = 69³).

The spelling of 328531 in words is "three hundred twenty-eight thousand, five hundred thirty-one".