521321 has 4 divisors (see below), whose sum is σ = 528000. Its totient is φ = 514644.

The previous prime is 521317. The next prime is 521329. The reversal of 521321 is 123125.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 521321 - 2² = 521317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 521296 and 521305.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 521321.

It is not an unprimeable number, because it can be changed into a prime (521329) 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, 3221 + ... + 3378.

It is an arithmetic number, because the mean of its divisors is an integer number (132000).

2⁵²¹³²¹ is an apocalyptic number.

It is an amenable number.

521321 is a deficient number, since it is larger than the sum of its proper divisors (6679).

521321 is an equidigital number, since it uses as much as digits as its factorization.

521321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6678.

The product of its digits is 60, while the sum is 14.

The square root of 521321 is about 722.0256228140. The cubic root of 521321 is about 80.4825521899.

Adding to 521321 its reverse (123125), we get a palindrome (644446).

The spelling of 521321 in words is "five hundred twenty-one thousand, three hundred twenty-one".