320521 has 2 divisors, whose sum is σ = 320522. Its totient is φ = 320520.

The previous prime is 320513. The next prime is 320533. The reversal of 320521 is 125023.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 319225 + 1296 = 565^2 + 36^2 .

It is a cyclic number.

It is not a de Polignac number, because 320521 - 2³ = 320513 is a prime.

It is a super-2 number, since 2×320521² = 205467422882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320561) 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, 160260 + 160261.

It is an arithmetic number, because the mean of its divisors is an integer number (160261).

2³²⁰⁵²¹ is an apocalyptic number.

It is an amenable number.

320521 is a deficient number, since it is larger than the sum of its proper divisors (1).

320521 is an equidigital number, since it uses as much as digits as its factorization.

320521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 320521 is about 566.1457409537. The cubic root of 320521 is about 68.4361384674.

Adding to 320521 its reverse (125023), we get a palindrome (445544).

It can be divided in two parts, 320 and 521, that added together give a square (841 = 29²).

The spelling of 320521 in words is "three hundred twenty thousand, five hundred twenty-one".