320405 has 4 divisors (see below), whose sum is σ = 384492. Its totient is φ = 256320.

The previous prime is 320401. The next prime is 320417. The reversal of 320405 is 504023.

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 111556 + 208849 = 334^2 + 457^2 .

It is not a de Polignac number, because 320405 - 2² = 320401 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 320405.

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 320405.

It is not an unprimeable number, because it can be changed into a prime (320401) 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, 32036 + ... + 32045.

It is an arithmetic number, because the mean of its divisors is an integer number (96123).

2³²⁰⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

320405 is a deficient number, since it is larger than the sum of its proper divisors (64087).

320405 is an equidigital number, since it uses as much as digits as its factorization.

320405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64086.

The product of its (nonzero) digits is 120, while the sum is 14.

The square root of 320405 is about 566.0432845640. The cubic root of 320405 is about 68.4278815462.

Adding to 320405 its reverse (504023), we get a palindrome (824428).

It can be divided in two parts, 320 and 405, that multiplied together give a square (129600 = 360²).

The spelling of 320405 in words is "three hundred twenty thousand, four hundred five".