550821 has 8 divisors (see below), whose sum is σ = 743040. Its totient is φ = 362912.

The previous prime is 550813. The next prime is 550831. The reversal of 550821 is 128055.

550821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 550821 - 2³ = 550813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (550801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 765 + ... + 1298.

It is an arithmetic number, because the mean of its divisors is an integer number (92880).

2⁵⁵⁰⁸²¹ is an apocalyptic number.

It is an amenable number.

550821 is a deficient number, since it is larger than the sum of its proper divisors (192219).

550821 is a wasteful number, since it uses less digits than its factorization.

550821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2155.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 550821 is about 742.1731603878. The cubic root of 550821 is about 81.9728742322.

Adding to 550821 its reverse (128055), we get a palindrome (678876).

The spelling of 550821 in words is "five hundred fifty thousand, eight hundred twenty-one".