320581 has 4 divisors (see below), whose sum is σ = 323532. Its totient is φ = 317632.

The previous prime is 320563. The next prime is 320591. The reversal of 320581 is 185023.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 185023 = 53 ⋅3491.

It can be written as a sum of positive squares in 2 ways, for example, as 8100 + 312481 = 90^2 + 559^2 .

It is a cyclic number.

It is not a de Polignac number, because 320581 - 2¹⁵ = 287813 is a prime.

It is a super-2 number, since 2×320581² = 205544355122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320521) 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, 1306 + ... + 1531.

It is an arithmetic number, because the mean of its divisors is an integer number (80883).

2³²⁰⁵⁸¹ is an apocalyptic number.

It is an amenable number.

320581 is a deficient number, since it is larger than the sum of its proper divisors (2951).

320581 is a wasteful number, since it uses less digits than its factorization.

320581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2950.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 320581 is about 566.1987283631. The cubic root of 320581 is about 68.4404085070.

The spelling of 320581 in words is "three hundred twenty thousand, five hundred eighty-one".