489821 has 4 divisors (see below), whose sum is σ = 518652. Its totient is φ = 460992.

The previous prime is 489817. The next prime is 489823. The reversal of 489821 is 128984.

It is a happy number.

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 225625 + 264196 = 475^2 + 514^2 .

It is a cyclic number.

It is not a de Polignac number, because 489821 - 2² = 489817 is a prime.

It is a super-2 number, since 2×489821² = 479849224082, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (489823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14390 + ... + 14423.

It is an arithmetic number, because the mean of its divisors is an integer number (129663).

2⁴⁸⁹⁸²¹ is an apocalyptic number.

It is an amenable number.

489821 is a deficient number, since it is larger than the sum of its proper divisors (28831).

489821 is a wasteful number, since it uses less digits than its factorization.

489821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28830.

The product of its digits is 4608, while the sum is 32.

The square root of 489821 is about 699.8721311783. The cubic root of 489821 is about 78.8277505394.

The spelling of 489821 in words is "four hundred eighty-nine thousand, eight hundred twenty-one".