539821 has 4 divisors (see below), whose sum is σ = 542812. Its totient is φ = 536832.

The previous prime is 539797. The next prime is 539837. The reversal of 539821 is 128935.

539821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 264196 + 275625 = 514^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 539821 - 2⁹ = 539309 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 539821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (539881) 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, 1206 + ... + 1591.

It is an arithmetic number, because the mean of its divisors is an integer number (135703).

2⁵³⁹⁸²¹ is an apocalyptic number.

It is an amenable number.

539821 is a deficient number, since it is larger than the sum of its proper divisors (2991).

539821 is a wasteful number, since it uses less digits than its factorization.

539821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2990.

The product of its digits is 2160, while the sum is 28.

The square root of 539821 is about 734.7251186668. The cubic root of 539821 is about 81.4235297117.

The spelling of 539821 in words is "five hundred thirty-nine thousand, eight hundred twenty-one".