530821 has 4 divisors (see below), whose sum is σ = 532332. Its totient is φ = 529312.

The previous prime is 530807. The next prime is 530833. The reversal of 530821 is 128035.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 122500 + 408321 = 350^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 530821 - 2⁷ = 530693 is a prime.

It is a Duffinian number.

530821 is a lucky number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (530851) 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 in 3 ways as a sum of consecutive naturals, for example, 81 + ... + 1033.

It is an arithmetic number, because the mean of its divisors is an integer number (133083).

2⁵³⁰⁸²¹ is an apocalyptic number.

It is an amenable number.

530821 is a deficient number, since it is larger than the sum of its proper divisors (1511).

530821 is an equidigital number, since it uses as much as digits as its factorization.

530821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1510.

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

The square root of 530821 is about 728.5746358473. The cubic root of 530821 is about 80.9684884793.

Adding to 530821 its reverse (128035), we get a palindrome (658856).

It can be divided in two parts, 5308 and 21, that added together give a square (5329 = 73²).

The spelling of 530821 in words is "five hundred thirty thousand, eight hundred twenty-one".